require 'daru/accessors/dataframe_by_row.rb'
require 'daru/maths/arithmetic/dataframe.rb'
require 'daru/maths/statistics/dataframe.rb'
require 'daru/plotting/gruff.rb'
require 'daru/plotting/nyaplot.rb'
require 'daru/io/io.rb'
module Daru
class DataFrame # rubocop:disable Metrics/ClassLength
include Daru::Maths::Arithmetic::DataFrame
include Daru::Maths::Statistics::DataFrame
# TODO: Remove this line but its causing erros due to unkown reason
Daru.has_nyaplot?
extend Gem::Deprecate
class << self
# Load data from a CSV file. Specify an optional block to grab the CSV
# object and pre-condition it (for example use the `convert` or
# `header_convert` methods).
#
# == Arguments
#
# * path - Local path / Remote URL of the file to load specified as a String.
#
# == Options
#
# Accepts the same options as the Daru::DataFrame constructor and CSV.open()
# and uses those to eventually construct the resulting DataFrame.
#
# == Verbose Description
#
# You can specify all the options to the `.from_csv` function that you
# do to the Ruby `CSV.read()` function, since this is what is used internally.
#
# For example, if the columns in your CSV file are separated by something
# other that commas, you can use the `:col_sep` option. If you want to
# convert numeric values to numbers and not keep them as strings, you can
# use the `:converters` option and set it to `:numeric`.
#
# The `.from_csv` function uses the following defaults for reading CSV files
# (that are passed into the `CSV.read()` function):
#
# {
# :col_sep => ',',
# :converters => :numeric
# }
def from_csv path, opts={}, &block
Daru::IO.from_csv path, opts, &block
end
# Read data from an Excel file into a DataFrame.
#
# == Arguments
#
# * path - Path of the file to be read.
#
# == Options
#
# *:worksheet_id - ID of the worksheet that is to be read.
def from_excel path, opts={}, &block
Daru::IO.from_excel path, opts, &block
end
# Read a database query and returns a Dataset
#
# @param dbh [DBI::DatabaseHandle, String] A DBI connection OR Path to a SQlite3 database.
# @param query [String] The query to be executed
#
# @return A dataframe containing the data resulting from the query
#
# USE:
#
# dbh = DBI.connect("DBI:Mysql:database:localhost", "user", "password")
# Daru::DataFrame.from_sql(dbh, "SELECT * FROM test")
#
# #Alternatively
#
# require 'dbi'
# Daru::DataFrame.from_sql("path/to/sqlite.db", "SELECT * FROM test")
def from_sql dbh, query
Daru::IO.from_sql dbh, query
end
# Read a dataframe from AR::Relation
#
# @param relation [ActiveRecord::Relation] An AR::Relation object from which data is loaded
# @param fields [Array] Field names to be loaded (optional)
#
# @return A dataframe containing the data loaded from the relation
#
# USE:
#
# # When Post model is defined as:
# class Post < ActiveRecord::Base
# scope :active, -> { where.not(published_at: nil) }
# end
#
# # You can load active posts into a dataframe by:
# Daru::DataFrame.from_activerecord(Post.active, :title, :published_at)
def from_activerecord relation, *fields
Daru::IO.from_activerecord relation, *fields
end
# Read the database from a plaintext file. For this method to work,
# the data should be present in a plain text file in columns. See
# spec/fixtures/bank2.dat for an example.
#
# == Arguments
#
# * path - Path of the file to be read.
# * fields - Vector names of the resulting database.
#
# == Usage
#
# df = Daru::DataFrame.from_plaintext 'spec/fixtures/bank2.dat', [:v1,:v2,:v3,:v4,:v5,:v6]
def from_plaintext path, fields
Daru::IO.from_plaintext path, fields
end
# Read the table data from a remote html file. Please note that this module
# works only for static table elements on a HTML page, and won't work in
# cases where the data is being loaded into the HTML table by Javascript.
#
# By default - all | tag elements in the first proper row are considered
# as the order, and all the | tag elements in the first column are
# considered as the index.
#
# == Arguments
#
# * path [String] - URL of the target HTML file.
# * fields [Hash] -
#
# +:match+ - A *String* to match and choose a particular table(s) from multiple tables of a HTML page.
#
# +:order+ - An *Array* which would act as the user-defined order, to override the parsed *Daru::DataFrame*.
#
# +:index+ - An *Array* which would act as the user-defined index, to override the parsed *Daru::DataFrame*.
#
# +:name+ - A *String* that manually assigns a name to the scraped *Daru::DataFrame*, for user's preference.
#
# == Returns
# An Array of +Daru::DataFrame+s, with each dataframe corresponding to a
# HTML table on that webpage.
#
# == Usage
# dfs = Daru::DataFrame.from_html("http://www.moneycontrol.com/", match: "Sun Pharma")
# dfs.count
# # => 4
#
# dfs.first
# #
# # =>
# # Company Price Change Value (Rs
# # 0 Sun Pharma 502.60 -65.05 2,117.87
# # 1 Reliance 1356.90 19.60 745.10
# # 2 Tech Mahin 379.45 -49.70 650.22
# # 3 ITC 315.85 6.75 621.12
# # 4 HDFC 1598.85 50.95 553.91
def from_html path, fields={}
Daru::IO.from_html path, fields
end
# Create DataFrame by specifying rows as an Array of Arrays or Array of
# Daru::Vector objects.
def rows source, opts={}
raise SizeError, 'All vectors must have same length' \
unless source.all? { |v| v.size == source.first.size }
opts[:order] ||= guess_order(source)
if ArrayHelper.array_of?(source, Array) || source.empty?
DataFrame.new(source.transpose, opts)
elsif ArrayHelper.array_of?(source, Vector)
from_vector_rows(source, opts)
else
raise ArgumentError, "Can't create DataFrame from #{source}"
end
end
# Generates a new dataset, using three vectors
# - Rows
# - Columns
# - Values
#
# For example, you have these values
#
# x y v
# a a 0
# a b 1
# b a 1
# b b 0
#
# You obtain
# id a b
# a 0 1
# b 1 0
#
# Useful to process outputs from databases
def crosstab_by_assignation rows, columns, values
raise 'Three vectors should be equal size' if
rows.size != columns.size || rows.size!=values.size
data = Hash.new { |h, col|
h[col] = rows.factors.map { |r| [r, nil] }.to_h
}
columns.zip(rows, values).each { |c, r, v| data[c][r] = v }
# FIXME: in fact, WITHOUT this line you'll obtain more "right"
# data: with vectors having "rows" as an index...
data = data.map { |c, r| [c, r.values] }.to_h
data[:_id] = rows.factors
DataFrame.new(data)
end
private
def guess_order source
case source.first
when Vector # assume that all are Vectors
source.first.index.to_a
when Array
Array.new(source.first.size, &:to_s)
end
end
def from_vector_rows source, opts
index = source.map(&:name)
.each_with_index.map { |n, i| n || i }
index = ArrayHelper.recode_repeated(index)
DataFrame.new({}, opts).tap do |df|
source.each_with_index do |row, idx|
df[index[idx] || idx, :row] = row
end
end
end
end
# The vectors (columns) index of the DataFrame
attr_reader :vectors
# TOREMOVE
attr_reader :data
# The index of the rows of the DataFrame
attr_reader :index
# The name of the DataFrame
attr_reader :name
# The number of rows present in the DataFrame
attr_reader :size
# DataFrame basically consists of an Array of Vector objects.
# These objects are indexed by row and column by vectors and index Index objects.
#
# == Arguments
#
# * source - Source from the DataFrame is to be initialized. Can be a Hash
# of names and vectors (array or Daru::Vector), an array of arrays or
# array of Daru::Vectors.
#
# == Options
#
# +:order+ - An *Array*/*Daru::Index*/*Daru::MultiIndex* containing the order in
# which Vectors should appear in the DataFrame.
#
# +:index+ - An *Array*/*Daru::Index*/*Daru::MultiIndex* containing the order
# in which rows of the DataFrame will be named.
#
# +:name+ - A name for the DataFrame.
#
# +:clone+ - Specify as *true* or *false*. When set to false, and Vector
# objects are passed for the source, the Vector objects will not duplicated
# when creating the DataFrame. Will have no effect if Array is passed in
# the source, or if the passed Daru::Vectors have different indexes.
# Default to *true*.
#
# == Usage
#
# df = Daru::DataFrame.new
# # =>
# #
# # Creates an empty DataFrame with no rows or columns.
#
# df = Daru::DataFrame.new({}, order: [:a, :b])
# #
# a b
# # Creates a DataFrame with no rows and columns :a and :b
#
# df = Daru::DataFrame.new({a: [1,2,3,4], b: [6,7,8,9]}, order: [:b, :a],
# index: [:a, :b, :c, :d], name: :spider_man)
#
# # =>
# #
# # b a
# # a 6 1
# # b 7 2
# # c 8 3
# # d 9 4
#
# df = Daru::DataFrame.new([[1,2,3,4],[6,7,8,9]], name: :bat_man)
#
# # =>
# # #
# # 0 1
# # 0 1 6
# # 1 2 7
# # 2 3 8
# # 3 4 9
#
# # Dataframe having Index name
#
# df = Daru::DataFrame.new({a: [1,2,3,4], b: [6,7,8,9]}, order: [:b, :a],
# index: Daru::Index.new([:a, :b, :c, :d], name: 'idx_name'),
# name: :spider_man)
#
# # =>
# #
# # idx_name b a
# # a 6 1
# # b 7 2
# # c 8 3
# # d 9 4
#
#
# idx = Daru::Index.new [100, 99, 101, 1, 2], name: "s1"
# => #
#
# df = Daru::DataFrame.new({b: [11,12,13,14,15], a: [1,2,3,4,5],
# c: [11,22,33,44,55]},
# order: [:a, :b, :c],
# index: idx)
# # =>
# #
# # s1 a b c
# # 100 1 11 11
# # 99 2 12 22
# # 101 3 13 33
# # 1 4 14 44
# # 2 5 15 55
def initialize source={}, opts={} # rubocop:disable Metrics/MethodLength
vectors, index = opts[:order], opts[:index] # FIXME: just keyword arges after Ruby 2.1
@data = []
@name = opts[:name]
case source
when [], {}
create_empty_vectors(vectors, index)
when Array
initialize_from_array source, vectors, index, opts
when Hash
initialize_from_hash source, vectors, index, opts
when ->(s) { s.empty? } # TODO: likely want to remove this case
create_empty_vectors(vectors, index)
end
set_size
validate
update
end
def plotting_library= lib
case lib
when :gruff, :nyaplot
@plotting_library = lib
if Daru.send("has_#{lib}?".to_sym)
extend Module.const_get(
"Daru::Plotting::DataFrame::#{lib.to_s.capitalize}Library"
)
end
else
raise ArgumentError, "Plotting library #{lib} not supported. "\
'Supported libraries are :nyaplot and :gruff'
end
end
# this method is overwritten: see Daru::DataFrame#plotting_library=
def plot(*args, **options, &b)
init_plotting_library
plot(*args, **options, &b)
end
# Access row or vector. Specify name of row/vector followed by axis(:row, :vector).
# Defaults to *:vector*. Use of this method is not recommended for accessing
# rows. Use df.row[:a] for accessing row with index ':a'.
def [](*names)
axis = extract_axis(names, :vector)
dispatch_to_axis axis, :access, *names
end
# Retrive rows by positions
# @param [Array] positions of rows to retrive
# @return [Daru::Vector, Daru::DataFrame] vector for single position and dataframe for multiple positions
# @example
# df = Daru::DataFrame.new({
# a: [1, 2, 3],
# b: ['a', 'b', 'c']
# })
# df.row_at 1, 2
# # => #
# # a b
# # 1 2 b
# # 2 3 c
def row_at *positions
original_positions = positions
positions = coerce_positions(*positions, nrows)
validate_positions(*positions, nrows)
if positions.is_a? Integer
row = get_rows_for([positions])
Daru::Vector.new row, index: @vectors
else
new_rows = get_rows_for(original_positions)
Daru::DataFrame.new new_rows, index: @index.at(*original_positions), order: @vectors
end
end
# Set rows by positions
# @param [Array] positions positions of rows to set
# @param [Array, Daru::Vector] vector vector to be assigned
# @example
# df = Daru::DataFrame.new({
# a: [1, 2, 3],
# b: ['a', 'b', 'c']
# })
# df.set_row_at [0, 1], ['x', 'x']
# df
# #=> #
# # a b
# # 0 x x
# # 1 x x
# # 2 3 c
def set_row_at positions, vector
validate_positions(*positions, nrows)
vector =
if vector.is_a? Daru::Vector
vector.reindex @vectors
else
Daru::Vector.new vector
end
raise SizeError, 'Vector length should match row length' if
vector.size != @vectors.size
@data.each_with_index do |vec, pos|
vec.set_at(positions, vector.at(pos))
end
@index = @data[0].index
set_size
end
# Retrive vectors by positions
# @param [Array] positions of vectors to retrive
# @return [Daru::Vector, Daru::DataFrame] vector for single position and dataframe for multiple positions
# @example
# df = Daru::DataFrame.new({
# a: [1, 2, 3],
# b: ['a', 'b', 'c']
# })
# df.at 0
# # => #
# # a
# # 0 1
# # 1 2
# # 2 3
def at *positions
if AXES.include? positions.last
axis = positions.pop
return row_at(*positions) if axis == :row
end
original_positions = positions
positions = coerce_positions(*positions, ncols)
validate_positions(*positions, ncols)
if positions.is_a? Integer
@data[positions].dup
else
Daru::DataFrame.new positions.map { |pos| @data[pos].dup },
index: @index,
order: @vectors.at(*original_positions),
name: @name
end
end
# Set vectors by positions
# @param [Array] positions positions of vectors to set
# @param [Array, Daru::Vector] vector vector to be assigned
# @example
# df = Daru::DataFrame.new({
# a: [1, 2, 3],
# b: ['a', 'b', 'c']
# })
# df.set_at [0], ['x', 'y', 'z']
# df
# #=> #
# # a b
# # 0 x a
# # 1 y b
# # 2 z c
def set_at positions, vector
if positions.last == :row
positions.pop
return set_row_at(positions, vector)
end
validate_positions(*positions, ncols)
vector =
if vector.is_a? Daru::Vector
vector.reindex @index
else
Daru::Vector.new vector
end
raise SizeError, 'Vector length should match index length' if
vector.size != @index.size
positions.each { |pos| @data[pos] = vector }
end
# Insert a new row/vector of the specified name or modify a previous row.
# Instead of using this method directly, use df.row[:a] = [1,2,3] to set/create
# a row ':a' to [1,2,3], or df.vector[:vec] = [1,2,3] for vectors.
#
# In case a Daru::Vector is specified after the equality the sign, the indexes
# of the vector will be matched against the row/vector indexes of the DataFrame
# before an insertion is performed. Unmatched indexes will be set to nil.
def []=(*args)
vector = args.pop
axis = extract_axis(args)
names = args
dispatch_to_axis axis, :insert_or_modify, names, vector
end
def add_row row, index=nil
self.row[*(index || @size)] = row
end
def add_vector n, vector
self[n] = vector
end
# Access a row or set/create a row. Refer #[] and #[]= docs for details.
#
# == Usage
# df.row[:a] # access row named ':a'
# df.row[:b] = [1,2,3] # set row ':b' to [1,2,3]
def row
Daru::Accessors::DataFrameByRow.new(self)
end
# Extract a dataframe given row indexes or positions
# @param keys [Array] can be positions (if by_position is true) or indexes (if by_position if false)
# @return [Daru::Dataframe]
def get_sub_dataframe(keys, by_position: true)
return Daru::DataFrame.new({}) if keys == []
keys = @index.pos(*keys) unless by_position
sub_df = row_at(*keys)
sub_df = sub_df.to_df.transpose if sub_df.is_a?(Daru::Vector)
sub_df
end
# Duplicate the DataFrame entirely.
#
# == Arguments
#
# * +vectors_to_dup+ - An Array specifying the names of Vectors to
# be duplicated. Will duplicate the entire DataFrame if not specified.
def dup vectors_to_dup=nil
vectors_to_dup = @vectors.to_a unless vectors_to_dup
src = vectors_to_dup.map { |vec| @data[@vectors.pos(vec)].dup }
new_order = Daru::Index.new(vectors_to_dup)
Daru::DataFrame.new src, order: new_order, index: @index.dup, name: @name, clone: true
end
# Only clone the structure of the DataFrame.
def clone_structure
Daru::DataFrame.new([], order: @vectors.dup, index: @index.dup, name: @name)
end
# Returns a 'view' of the DataFrame, i.e the object ID's of vectors are
# preserved.
#
# == Arguments
#
# +vectors_to_clone+ - Names of vectors to clone. Optional. Will return
# a view of the whole data frame otherwise.
def clone *vectors_to_clone
vectors_to_clone.flatten! if ArrayHelper.array_of?(vectors_to_clone, Array)
vectors_to_clone = @vectors.to_a if vectors_to_clone.empty?
h = vectors_to_clone.map { |vec| [vec, self[vec]] }.to_h
Daru::DataFrame.new(h, clone: false, order: vectors_to_clone, name: @name)
end
# Returns a 'shallow' copy of DataFrame if missing data is not present,
# or a full copy of only valid data if missing data is present.
def clone_only_valid
if include_values?(*Daru::MISSING_VALUES)
reject_values(*Daru::MISSING_VALUES)
else
clone
end
end
# Creates a new duplicate dataframe containing only rows
# without a single missing value.
def dup_only_valid vecs=nil
rows_with_nil = @data.map { |vec| vec.indexes(*Daru::MISSING_VALUES) }
.inject(&:concat)
.uniq
row_indexes = @index.to_a
(vecs.nil? ? self : dup(vecs)).row[*(row_indexes - rows_with_nil)]
end
deprecate :dup_only_valid, :reject_values, 2016, 10
# Returns a dataframe in which rows with any of the mentioned values
# are ignored.
# @param [Array] values to reject to form the new dataframe
# @return [Daru::DataFrame] Data Frame with only rows which doesn't
# contain the mentioned values
# @example
# df = Daru::DataFrame.new({
# a: [1, 2, 3, nil, Float::NAN, nil, 1, 7],
# b: [:a, :b, nil, Float::NAN, nil, 3, 5, 8],
# c: ['a', Float::NAN, 3, 4, 3, 5, nil, 7]
# }, index: 11..18)
# df.reject_values nil, Float::NAN
# # => #
# # a b c
# # 11 1 a a
# # 18 7 8 7
def reject_values(*values)
positions =
size.times.to_a - @data.flat_map { |vec| vec.positions(*values) }
# Handle the case when positions size is 1 and #row_at wouldn't return a df
if positions.size == 1
pos = positions.first
row_at(pos..pos)
else
row_at(*positions)
end
end
# Replace specified values with given value
# @param [Array] old_values values to replace with new value
# @param [object] new_value new value to replace with
# @return [Daru::DataFrame] Data Frame itself with old values replace
# with new value
# @example
# df = Daru::DataFrame.new({
# a: [1, 2, 3, nil, Float::NAN, nil, 1, 7],
# b: [:a, :b, nil, Float::NAN, nil, 3, 5, 8],
# c: ['a', Float::NAN, 3, 4, 3, 5, nil, 7]
# }, index: 11..18)
# df.replace_values nil, Float::NAN
# # => #
# # a b c
# # 11 1 a a
# # 12 2 b NaN
# # 13 3 NaN 3
# # 14 NaN NaN 4
# # 15 NaN NaN 3
# # 16 NaN 3 5
# # 17 1 5 NaN
# # 18 7 8 7
def replace_values old_values, new_value
@data.each { |vec| vec.replace_values old_values, new_value }
self
end
# Rolling fillna
# replace all Float::NAN and NIL values with the preceeding or following value
#
# @param direction [Symbol] (:forward, :backward) whether replacement value is preceeding or following
#
# @example
# df = Daru::DataFrame.new({
# a: [1, 2, 3, nil, Float::NAN, nil, 1, 7],
# b: [:a, :b, nil, Float::NAN, nil, 3, 5, nil],
# c: ['a', Float::NAN, 3, 4, 3, 5, nil, 7]
# })
#
# => #
# a b c
# 0 1 a a
# 1 2 b NaN
# 2 3 nil 3
# 3 nil NaN 4
# 4 NaN nil 3
# 5 nil 3 5
# 6 1 5 nil
# 7 7 nil 7
#
# 2.3.3 :068 > df.rolling_fillna(:forward)
# => #
# a b c
# 0 1 a a
# 1 2 b a
# 2 3 b 3
# 3 3 b 4
# 4 3 b 3
# 5 3 3 5
# 6 1 5 5
# 7 7 5 7
#
def rolling_fillna!(direction=:forward)
@data.each { |vec| vec.rolling_fillna!(direction) }
self
end
def rolling_fillna(direction=:forward)
dup.rolling_fillna!(direction)
end
# Return unique rows by vector specified or all vectors
#
# @param vtrs [String][Symbol] vector names(s) that should be considered
#
# @example
#
# => #
# a b
# 0 1 a
# 1 2 b
# 2 3 c
# 3 4 d
# 2 3 c
# 3 4 f
#
# 2.3.3 :> df.unique
# => #
# a b
# 0 1 a
# 1 2 b
# 2 3 c
# 3 4 d
# 3 4 f
#
# 2.3.3 :> df.unique(:a)
# => #
# a b
# 0 1 a
# 1 2 b
# 2 3 c
# 3 4 d
#
def uniq(*vtrs)
vecs = vtrs.empty? ? vectors.to_a : Array(vtrs)
grouped = group_by(vecs)
indexes = grouped.groups.values.map { |v| v[0] }.sort
row[*indexes]
end
# Iterate over each index of the DataFrame.
def each_index &block
return to_enum(:each_index) unless block_given?
@index.each(&block)
self
end
# Iterate over each vector
def each_vector(&block)
return to_enum(:each_vector) unless block_given?
@data.each(&block)
self
end
alias_method :each_column, :each_vector
# Iterate over each vector alongwith the name of the vector
def each_vector_with_index
return to_enum(:each_vector_with_index) unless block_given?
@vectors.each do |vector|
yield @data[@vectors[vector]], vector
end
self
end
alias_method :each_column_with_index, :each_vector_with_index
# Iterate over each row
def each_row
return to_enum(:each_row) unless block_given?
@index.size.times do |pos|
yield row_at(pos)
end
self
end
def each_row_with_index
return to_enum(:each_row_with_index) unless block_given?
@index.each do |index|
yield access_row(index), index
end
self
end
# Iterate over each row or vector of the DataFrame. Specify axis
# by passing :vector or :row as the argument. Default to :vector.
#
# == Description
#
# `#each` works exactly like Array#each. The default mode for `each`
# is to iterate over the columns of the DataFrame. To iterate over
# rows you must pass the axis, i.e `:row` as an argument.
#
# == Arguments
#
# * +axis+ - The axis to iterate over. Can be :vector (or :column)
# or :row. Default to :vector.
def each axis=:vector, &block
dispatch_to_axis axis, :each, &block
end
# Iterate over a row or vector and return results in a Daru::Vector.
# Specify axis with :vector or :row. Default to :vector.
#
# == Description
#
# The #collect iterator works similar to #map, the only difference
# being that it returns a Daru::Vector comprising of the results of
# each block run. The resultant Vector has the same index as that
# of the axis over which collect has iterated. It also accepts the
# optional axis argument.
#
# == Arguments
#
# * +axis+ - The axis to iterate over. Can be :vector (or :column)
# or :row. Default to :vector.
def collect axis=:vector, &block
dispatch_to_axis_pl axis, :collect, &block
end
# Map over each vector or row of the data frame according to
# the argument specified. Will return an Array of the resulting
# elements. To map over each row/vector and get a DataFrame,
# see #recode.
#
# == Description
#
# The #map iterator works like Array#map. The value returned by
# each run of the block is added to an Array and the Array is
# returned. This method also accepts an axis argument, like #each.
# The default is :vector.
#
# == Arguments
#
# * +axis+ - The axis to map over. Can be :vector (or :column) or :row.
# Default to :vector.
def map axis=:vector, &block
dispatch_to_axis_pl axis, :map, &block
end
# Destructive map. Modifies the DataFrame. Each run of the block
# must return a Daru::Vector. You can specify the axis to map over
# as the argument. Default to :vector.
#
# == Arguments
#
# * +axis+ - The axis to map over. Can be :vector (or :column) or :row.
# Default to :vector.
def map! axis=:vector, &block
if %i[vector column].include?(axis)
map_vectors!(&block)
elsif axis == :row
map_rows!(&block)
end
end
# Maps over the DataFrame and returns a DataFrame. Each run of the
# block must return a Daru::Vector object. You can specify the axis
# to map over. Default to :vector.
#
# == Description
#
# Recode works similarly to #map, but an important difference between
# the two is that recode returns a modified Daru::DataFrame instead
# of an Array. For this reason, #recode expects that every run of the
# block to return a Daru::Vector.
#
# Just like map and each, recode also accepts an optional _axis_ argument.
#
# == Arguments
#
# * +axis+ - The axis to map over. Can be :vector (or :column) or :row.
# Default to :vector.
def recode axis=:vector, &block
dispatch_to_axis_pl axis, :recode, &block
end
# Retain vectors or rows if the block returns a truthy value.
#
# == Description
#
# For filtering out certain rows/vectors based on their values,
# use the #filter method. By default it iterates over vectors and
# keeps those vectors for which the block returns true. It accepts
# an optional axis argument which lets you specify whether you want
# to iterate over vectors or rows.
#
# == Arguments
#
# * +axis+ - The axis to map over. Can be :vector (or :column) or :row.
# Default to :vector.
#
# == Usage
#
# # Filter vectors
#
# df.filter do |vector|
# vector.type == :numeric and vector.median < 50
# end
#
# # Filter rows
#
# df.filter(:row) do |row|
# row[:a] + row[:d] < 100
# end
def filter axis=:vector, &block
dispatch_to_axis_pl axis, :filter, &block
end
def recode_vectors
block_given? or return to_enum(:recode_vectors)
dup.tap do |df|
df.each_vector_with_index do |v, i|
df[*i] = should_be_vector!(yield(v))
end
end
end
def recode_rows
block_given? or return to_enum(:recode_rows)
dup.tap do |df|
df.each_row_with_index do |r, i|
df.row[i] = should_be_vector!(yield(r))
end
end
end
# Map each vector and return an Array.
def map_vectors &block
return to_enum(:map_vectors) unless block_given?
@data.map(&block)
end
# Destructive form of #map_vectors
def map_vectors!
return to_enum(:map_vectors!) unless block_given?
vectors.dup.each do |n|
self[n] = should_be_vector!(yield(self[n]))
end
self
end
# Map vectors alongwith the index.
def map_vectors_with_index &block
return to_enum(:map_vectors_with_index) unless block_given?
each_vector_with_index.map(&block)
end
# Map each row
def map_rows &block
return to_enum(:map_rows) unless block_given?
each_row.map(&block)
end
def map_rows_with_index &block
return to_enum(:map_rows_with_index) unless block_given?
each_row_with_index.map(&block)
end
def map_rows!
return to_enum(:map_rows!) unless block_given?
index.dup.each do |i|
row[i] = should_be_vector!(yield(row[i]))
end
self
end
def apply_method(method, keys: nil, by_position: true)
df = keys ? get_sub_dataframe(keys, by_position: by_position) : self
case method
when Symbol then df.send(method)
when Proc then method.call(df)
when Array then method.map(&:to_proc).map { |proc| proc.call(df) } # works with Array of both Symbol and/or Proc
else raise
end
end
alias :apply_method_on_sub_df :apply_method
# Retrieves a Daru::Vector, based on the result of calculation
# performed on each row.
def collect_rows &block
return to_enum(:collect_rows) unless block_given?
Daru::Vector.new(each_row.map(&block), index: @index)
end
def collect_row_with_index &block
return to_enum(:collect_row_with_index) unless block_given?
Daru::Vector.new(each_row_with_index.map(&block), index: @index)
end
# Retrives a Daru::Vector, based on the result of calculation
# performed on each vector.
def collect_vectors &block
return to_enum(:collect_vectors) unless block_given?
Daru::Vector.new(each_vector.map(&block), index: @vectors)
end
def collect_vector_with_index &block
return to_enum(:collect_vector_with_index) unless block_given?
Daru::Vector.new(each_vector_with_index.map(&block), index: @vectors)
end
# Generate a matrix, based on vector names of the DataFrame.
#
# @return {::Matrix}
# :nocov:
# FIXME: Even not trying to cover this: I can't get, how it is expected
# to work.... -- zverok
def collect_matrix
return to_enum(:collect_matrix) unless block_given?
vecs = vectors.to_a
rows = vecs.collect { |row|
vecs.collect { |col|
yield row,col
}
}
Matrix.rows(rows)
end
# :nocov:
# Delete a vector
def delete_vector vector
raise IndexError, "Vector #{vector} does not exist." unless @vectors.include?(vector)
@data.delete_at @vectors[vector]
@vectors = Daru::Index.new @vectors.to_a - [vector]
self
end
# Deletes a list of vectors
def delete_vectors *vectors
Array(vectors).each { |vec| delete_vector vec }
self
end
# Delete a row
def delete_row index
idx = named_index_for index
raise IndexError, "Index #{index} does not exist." unless @index.include? idx
@index = Daru::Index.new(@index.to_a - [idx])
each_vector do |vector|
vector.delete_at idx
end
set_size
end
# Creates a DataFrame with the random data, of n size.
# If n not given, uses original number of rows.
#
# @return {Daru::DataFrame}
def bootstrap(n=nil)
n ||= nrows
Daru::DataFrame.new({}, order: @vectors).tap do |df_boot|
n.times do
df_boot.add_row(row[rand(n)])
end
df_boot.update
end
end
def keep_row_if
@index
.reject { |idx| yield access_row(idx) }
.each { |idx| delete_row idx }
end
def keep_vector_if
@vectors.each do |vector|
delete_vector(vector) unless yield(@data[@vectors[vector]], vector)
end
end
# creates a new vector with the data of a given field which the block returns true
def filter_vector vec, &block
Daru::Vector.new(each_row.select(&block).map { |row| row[vec] })
end
# Iterates over each row and retains it in a new DataFrame if the block returns
# true for that row.
def filter_rows
return to_enum(:filter_rows) unless block_given?
keep_rows = @index.map { |index| yield access_row(index) }
where keep_rows
end
# Iterates over each vector and retains it in a new DataFrame if the block returns
# true for that vector.
def filter_vectors &block
return to_enum(:filter_vectors) unless block_given?
dup.tap { |df| df.keep_vector_if(&block) }
end
# Test each row with one or more tests.
# @param tests [Proc] Each test is a Proc with the form
# *Proc.new {|row| row[:age] > 0}*
# The function returns an array with all errors.
#
# FIXME: description here is too sparse. As far as I can get,
# it should tell something about that each test is [descr, fields, block],
# and that first value may be column name to output. - zverok, 2016-05-18
def verify(*tests)
id = tests.first.is_a?(Symbol) ? tests.shift : @vectors.first
each_row_with_index.map do |row, i|
tests.reject { |*_, block| block.call(row) }
.map { |test| verify_error_message row, test, id, i }
end.flatten
end
# DSL for yielding each row and returning a Daru::Vector based on the
# value each run of the block returns.
#
# == Usage
#
# a1 = Daru::Vector.new([1, 2, 3, 4, 5, 6, 7])
# a2 = Daru::Vector.new([10, 20, 30, 40, 50, 60, 70])
# a3 = Daru::Vector.new([100, 200, 300, 400, 500, 600, 700])
# ds = Daru::DataFrame.new({ :a => a1, :b => a2, :c => a3 })
# total = ds.vector_by_calculation { a + b + c }
# #
# # nil
# # 0 111
# # 1 222
# # 2 333
# # 3 444
# # 4 555
# # 5 666
# # 6 777
def vector_by_calculation &block
a = each_row.map { |r| r.instance_eval(&block) }
Daru::Vector.new a, index: @index
end
# Reorder the vectors in a dataframe
# @param [Array] order_array new order of the vectors
# @example
# df = Daru::DataFrame({
# a: [1, 2, 3],
# b: [4, 5, 6]
# }, order: [:a, :b])
# df.order = [:b, :a]
# df
# # => #
# # b a
# # 0 4 1
# # 1 5 2
# # 2 6 3
def order=(order_array)
raise ArgumentError, 'Invalid order' unless
order_array.sort == vectors.to_a.sort
initialize(to_h, order: order_array)
end
# Returns a vector, based on a string with a calculation based
# on vector.
#
# The calculation will be eval'ed, so you can put any variable
# or expression valid on ruby.
#
# For example:
# a = Daru::Vector.new [1,2]
# b = Daru::Vector.new [3,4]
# ds = Daru::DataFrame.new({:a => a,:b => b})
# ds.compute("a+b")
# => Vector [4,6]
def compute text, &block
return instance_eval(&block) if block_given?
instance_eval(text)
end
# Return a vector with the number of missing values in each row.
#
# == Arguments
#
# * +missing_values+ - An Array of the values that should be
# treated as 'missing'. The default missing value is *nil*.
def missing_values_rows missing_values=[nil]
number_of_missing = each_row.map do |row|
row.indexes(*missing_values).size
end
Daru::Vector.new number_of_missing, index: @index, name: "#{@name}_missing_rows"
end
# TODO: remove next version
alias :vector_missing_values :missing_values_rows
def has_missing_data?
@data.any? { |vec| vec.include_values?(*Daru::MISSING_VALUES) }
end
alias :flawed? :has_missing_data?
deprecate :has_missing_data?, :include_values?, 2016, 10
deprecate :flawed?, :include_values?, 2016, 10
# Check if any of given values occur in the data frame
# @param [Array] values to check for
# @return [true, false] true if any of the given values occur in the
# dataframe, false otherwise
# @example
# df = Daru::DataFrame.new({
# a: [1, 2, 3, nil, Float::NAN, nil, 1, 7],
# b: [:a, :b, nil, Float::NAN, nil, 3, 5, 8],
# c: ['a', Float::NAN, 3, 4, 3, 5, nil, 7]
# }, index: 11..18)
# df.include_values? nil
# # => true
def include_values?(*values)
@data.any? { |vec| vec.include_values?(*values) }
end
# Return a nested hash using vector names as keys and an array constructed of
# hashes with other values. If block provided, is used to provide the
# values, with parameters +row+ of dataset, +current+ last hash on
# hierarchy and +name+ of the key to include
def nest *tree_keys, &_block
tree_keys = tree_keys[0] if tree_keys[0].is_a? Array
each_row.each_with_object({}) do |row, current|
# Create tree
*keys, last = tree_keys
current = keys.inject(current) { |c, f| c[row[f]] ||= {} }
name = row[last]
if block_given?
current[name] = yield(row, current, name)
else
current[name] ||= []
current[name].push(row.to_h.delete_if { |key,_value| tree_keys.include? key })
end
end
end
def vector_count_characters vecs=nil
vecs ||= @vectors.to_a
collect_rows do |row|
vecs.map { |v| row[v].to_s.size }.inject(:+)
end
end
def add_vectors_by_split(name,join='-',sep=Daru::SPLIT_TOKEN)
self[name]
.split_by_separator(sep)
.each { |k,v| self["#{name}#{join}#{k}".to_sym] = v }
end
# Return the number of rows and columns of the DataFrame in an Array.
def shape
[nrows, ncols]
end
# The number of rows
def nrows
@index.size
end
# The number of vectors
def ncols
@vectors.size
end
# Check if a vector is present
def has_vector? vector
@vectors.include? vector
end
# Works like Array#any?.
#
# @param [Symbol] axis (:vector) The axis to iterate over. Can be :vector or
# :row. A Daru::Vector object is yielded in the block.
# @example Using any?
# df = Daru::DataFrame.new({a: [1,2,3,4,5], b: ['a', 'b', 'c', 'd', 'e']})
# df.any?(:row) do |row|
# row[:a] < 3 and row[:b] == 'b'
# end #=> true
def any? axis=:vector, &block
if %i[vector column].include?(axis)
@data.any?(&block)
elsif axis == :row
each_row do |row|
return true if yield(row)
end
false
else
raise ArgumentError, "Unidentified axis #{axis}"
end
end
# Works like Array#all?
#
# @param [Symbol] axis (:vector) The axis to iterate over. Can be :vector or
# :row. A Daru::Vector object is yielded in the block.
# @example Using all?
# df = Daru::DataFrame.new({a: [1,2,3,4,5], b: ['a', 'b', 'c', 'd', 'e']})
# df.all?(:row) do |row|
# row[:a] < 10
# end #=> true
def all? axis=:vector, &block
if %i[vector column].include?(axis)
@data.all?(&block)
elsif axis == :row
each_row.all?(&block)
else
raise ArgumentError, "Unidentified axis #{axis}"
end
end
# The first ten elements of the DataFrame
#
# @param [Fixnum] quantity (10) The number of elements to display from the top.
def head quantity=10
row.at 0..(quantity-1)
end
alias :first :head
# The last ten elements of the DataFrame
#
# @param [Fixnum] quantity (10) The number of elements to display from the bottom.
def tail quantity=10
start = [-quantity, -size].max
row.at start..-1
end
alias :last :tail
# Sum all numeric/specified vectors in the DataFrame.
#
# Returns a new vector that's a containing a sum of all numeric
# or specified vectors of the DataFrame. By default, if the vector
# contains a nil, the sum is nil.
# With :skipnil argument set to true, nil values are assumed to be
# 0 (zero) and the sum vector is returned.
#
# @param args [Array] List of vectors to sum. Default is nil in which case
# all numeric vectors are summed.
#
# @option opts [Boolean] :skipnil Consider nils as 0. Default is false.
#
# @return Vector with sum of all vectors specified in the argument.
# If vecs parameter is empty, sum all numeric vector.
#
# @example
# df = Daru::DataFrame.new({
# a: [1, 2, nil],
# b: [2, 1, 3],
# c: [1, 1, 1]
# })
# => #
# a b c
# 0 1 2 1
# 1 2 1 1
# 2 nil 3 1
# df.vector_sum [:a, :c]
# => #
# 0 2
# 1 3
# 2 nil
# df.vector_sum
# => #
# 0 4
# 1 4
# 2 nil
# df.vector_sum skipnil: true
# => #
# c
# 0 4
# 1 4
# 2 4
#
def vector_sum(*args)
defaults = {vecs: nil, skipnil: false}
options = args.last.is_a?(::Hash) ? args.pop : {}
options = defaults.merge(options)
vecs = args[0] || options[:vecs]
skipnil = args[1] || options[:skipnil]
vecs ||= numeric_vectors
sum = Daru::Vector.new [0]*@size, index: @index, name: @name, dtype: @dtype
vecs.inject(sum) { |memo, n| self[n].add(memo, skipnil: skipnil) }
end
# Calculate mean of the rows of the dataframe.
#
# == Arguments
#
# * +max_missing+ - The maximum number of elements in the row that can be
# zero for the mean calculation to happen. Default to 0.
def vector_mean max_missing=0
# FIXME: in vector_sum we preserve created vector dtype, but
# here we are not. Is this by design or ...? - zverok, 2016-05-18
mean_vec = Daru::Vector.new [0]*@size, index: @index, name: "mean_#{@name}"
each_row_with_index.each_with_object(mean_vec) do |(row, i), memo|
memo[i] = row.indexes(*Daru::MISSING_VALUES).size > max_missing ? nil : row.mean
end
end
# Group elements by vector to perform operations on them. Returns a
# Daru::Core::GroupBy object.See the Daru::Core::GroupBy docs for a detailed
# list of possible operations.
#
# == Arguments
#
# * vectors - An Array contatining names of vectors to group by.
#
# == Usage
#
# df = Daru::DataFrame.new({
# a: %w{foo bar foo bar foo bar foo foo},
# b: %w{one one two three two two one three},
# c: [1 ,2 ,3 ,1 ,3 ,6 ,3 ,8],
# d: [11 ,22 ,33 ,44 ,55 ,66 ,77 ,88]
# })
# df.group_by([:a,:b,:c]).groups
# #=> {["bar", "one", 2]=>[1],
# # ["bar", "three", 1]=>[3],
# # ["bar", "two", 6]=>[5],
# # ["foo", "one", 1]=>[0],
# # ["foo", "one", 3]=>[6],
# # ["foo", "three", 8]=>[7],
# # ["foo", "two", 3]=>[2, 4]}
def group_by *vectors
vectors.flatten!
missing = vectors - @vectors.to_a
unless missing.empty?
raise(ArgumentError, "Vector(s) missing: #{missing.join(', ')}")
end
vectors = [@vectors.first] if vectors.empty?
Daru::Core::GroupBy.new(self, vectors)
end
def reindex_vectors new_vectors
unless new_vectors.is_a?(Daru::Index)
raise ArgumentError, 'Must pass the new index of type Index or its '\
"subclasses, not #{new_vectors.class}"
end
cl = Daru::DataFrame.new({}, order: new_vectors, index: @index, name: @name)
new_vectors.each_with_object(cl) do |vec, memo|
memo[vec] = @vectors.include?(vec) ? self[vec] : [nil]*nrows
end
end
def get_vector_anyways(v)
@vectors.include?(v) ? self[v].to_a : [nil] * size
end
# Concatenate another DataFrame along corresponding columns.
# If columns do not exist in both dataframes, they are filled with nils
def concat other_df
vectors = (@vectors.to_a + other_df.vectors.to_a).uniq
data = vectors.map do |v|
get_vector_anyways(v).dup.concat(other_df.get_vector_anyways(v))
end
Daru::DataFrame.new(data, order: vectors)
end
# Concatenates another DataFrame as #concat.
# Additionally it tries to preserve the index. If the indices contain
# common elements, #union will overwrite the according rows in the
# first dataframe.
def union other_df
index = (@index.to_a + other_df.index.to_a).uniq
df = row[*(@index.to_a - other_df.index.to_a)]
df = df.concat(other_df)
df.index = Daru::Index.new(index)
df
end
module SetSingleIndexStrategy
def self.uniq_size(df, col)
df[col].uniq.size
end
def self.new_index(df, col)
Daru::Index.new(df[col].to_a)
end
def self.delete_vector(df, col)
df.delete_vector(col)
end
end
module SetMultiIndexStrategy
def self.uniq_size(df, cols)
df[*cols].uniq.size
end
def self.new_index(df, cols)
Daru::MultiIndex.from_arrays(df[*cols].map_vectors(&:to_a)).tap do |mi|
mi.name = cols
mi
end
end
def self.delete_vector(df, cols)
df.delete_vectors(*cols)
end
end
# Set a particular column as the new DF
def set_index new_index_col, opts={}
if new_index_col.respond_to?(:to_a)
strategy = SetMultiIndexStrategy
new_index_col = new_index_col.to_a
else
strategy = SetSingleIndexStrategy
end
uniq_size = strategy.uniq_size(self, new_index_col)
raise ArgumentError, 'All elements in new index must be unique.' if
@size != uniq_size
self.index = strategy.new_index(self, new_index_col)
strategy.delete_vector(self, new_index_col) unless opts[:keep]
self
end
# Change the index of the DataFrame and preserve the labels of the previous
# indexing. New index can be Daru::Index or any of its subclasses.
#
# @param [Daru::Index] new_index The new Index for reindexing the DataFrame.
# @example Reindexing DataFrame
# df = Daru::DataFrame.new({a: [1,2,3,4], b: [11,22,33,44]},
# index: ['a','b','c','d'])
# #=>
# ##
# # a b
# # a 1 11
# # b 2 22
# # c 3 33
# # d 4 44
# df.reindex Daru::Index.new(['b', 0, 'a', 'g'])
# #=>
# ##
# # a b
# # b 2 22
# # 0 nil nil
# # a 1 11
# # g nil nil
def reindex new_index
unless new_index.is_a?(Daru::Index)
raise ArgumentError, 'Must pass the new index of type Index or its '\
"subclasses, not #{new_index.class}"
end
cl = Daru::DataFrame.new({}, order: @vectors, index: new_index, name: @name)
new_index.each_with_object(cl) do |idx, memo|
memo.row[idx] = @index.include?(idx) ? row[idx] : [nil]*ncols
end
end
def reset_index
index_df = index.to_df
names = index.name
names = [names] unless names.instance_of?(Array)
new_vectors = names + vectors.to_a
self.index = index_df.index
names.each do |name|
self[name] = index_df[name]
end
self.order = new_vectors
self
end
# Reassign index with a new index of type Daru::Index or any of its subclasses.
#
# @param [Daru::Index] idx New index object on which the rows of the dataframe
# are to be indexed.
# @example Reassigining index of a DataFrame
# df = Daru::DataFrame.new({a: [1,2,3,4], b: [11,22,33,44]})
# df.index.to_a #=> [0,1,2,3]
#
# df.index = Daru::Index.new(['a','b','c','d'])
# df.index.to_a #=> ['a','b','c','d']
# df.row['a'].to_a #=> [1,11]
def index= idx
@index = Index.coerce idx
@data.each { |vec| vec.index = @index }
self
end
# Reassign vectors with a new index of type Daru::Index or any of its subclasses.
#
# @param new_index [Daru::Index] idx The new index object on which the vectors are to
# be indexed. Must of the same size as ncols.
# @example Reassigning vectors of a DataFrame
# df = Daru::DataFrame.new({a: [1,2,3,4], b: [:a,:b,:c,:d], c: [11,22,33,44]})
# df.vectors.to_a #=> [:a, :b, :c]
#
# df.vectors = Daru::Index.new([:foo, :bar, :baz])
# df.vectors.to_a #=> [:foo, :bar, :baz]
def vectors= new_index
unless new_index.is_a?(Daru::Index)
raise ArgumentError, 'Can only reindex with Index and its subclasses'
end
if new_index.size != ncols
raise ArgumentError, "Specified index length #{new_index.size} not equal to"\
"dataframe size #{ncols}"
end
@vectors = new_index
@data.zip(new_index.to_a).each do |vect, name|
vect.name = name
end
self
end
# Renames the vectors
#
# == Arguments
#
# * name_map - A hash where the keys are the exising vector names and
# the values are the new names. If a vector is renamed
# to a vector name that is already in use, the existing
# one is overwritten.
#
# == Usage
#
# df = Daru::DataFrame.new({ a: [1,2,3,4], b: [:a,:b,:c,:d], c: [11,22,33,44] })
# df.rename_vectors :a => :alpha, :c => :gamma
# df.vectors.to_a #=> [:alpha, :b, :gamma]
def rename_vectors name_map
existing_targets = name_map.reject { |k,v| k == v }.values & vectors.to_a
delete_vectors(*existing_targets)
new_names = vectors.to_a.map { |v| name_map[v] ? name_map[v] : v }
self.vectors = Daru::Index.new new_names
end
# Return the indexes of all the numeric vectors. Will include vectors with nils
# alongwith numbers.
def numeric_vectors
# FIXME: Why _with_index ?..
each_vector_with_index
.select { |vec, _i| vec.numeric? }
.map(&:last)
end
def numeric_vector_names
@vectors.select { |v| self[v].numeric? }
end
# Return a DataFrame of only the numerical Vectors. If clone: false
# is specified as option, only a *view* of the Vectors will be
# returned. Defaults to clone: true.
def only_numerics opts={}
cln = opts[:clone] == false ? false : true
arry = numeric_vectors.map { |v| self[v] }
order = Index.new(numeric_vectors)
Daru::DataFrame.new(arry, clone: cln, order: order, index: @index)
end
# Generate a summary of this DataFrame based on individual vectors in the DataFrame
# @return [String] String containing the summary of the DataFrame
def summary
summary = "= #{name}"
summary << "\n Number of rows: #{nrows}"
@vectors.each do |v|
summary << "\n Element:[#{v}]\n"
summary << self[v].summary(1)
end
summary
end
# Sorts a dataframe (ascending/descending) in the given pripority sequence of
# vectors, with or without a block.
#
# @param vector_order [Array] The order of vector names in which the DataFrame
# should be sorted.
# @param opts [Hash] opts The options to sort with.
# @option opts [TrueClass,FalseClass,Array] :ascending (true) Sort in ascending
# or descending order. Specify Array corresponding to *order* for multiple
# sort orders.
# @option opts [Hash] :by (lambda{|a| a }) Specify attributes of objects to
# to be used for sorting, for each vector name in *order* as a hash of
# vector name and lambda expressions. In case a lambda for a vector is not
# specified, the default will be used.
# @option opts [TrueClass,FalseClass,Array] :handle_nils (false) Handle nils
# automatically or not when a block is provided.
# If set to True, nils will appear at top after sorting.
#
# @example Sort a dataframe with a vector sequence.
#
#
# df = Daru::DataFrame.new({a: [1,2,1,2,3], b: [5,4,3,2,1]})
#
# df.sort [:a, :b]
# # =>
# #
# # a b
# # 2 1 3
# # 0 1 5
# # 3 2 2
# # 1 2 4
# # 4 3 1
#
# @example Sort a dataframe without a block. Here nils will be handled automatically.
#
# df = Daru::DataFrame.new({a: [-3,nil,-1,nil,5], b: [4,3,2,1,4]})
#
# df.sort([:a])
# # =>
# #
# # a b
# # 1 nil 3
# # 3 nil 1
# # 0 -3 4
# # 2 -1 2
# # 4 5 4
#
# @example Sort a dataframe with a block with nils handled automatically.
#
# df = Daru::DataFrame.new({a: [nil,-1,1,nil,-1,1], b: ['aaa','aa',nil,'baaa','x',nil] })
#
# df.sort [:b], by: {b: lambda { |a| a.length } }
# # NoMethodError: undefined method `length' for nil:NilClass
# # from (pry):8:in `block in __pry__'
#
# df.sort [:b], by: {b: lambda { |a| a.length } }, handle_nils: true
#
# # =>
# #
# # a b
# # 2 1 nil
# # 5 1 nil
# # 4 -1 x
# # 1 -1 aa
# # 0 nil aaa
# # 3 nil baaa
#
# @example Sort a dataframe with a block with nils handled manually.
#
# df = Daru::DataFrame.new({a: [nil,-1,1,nil,-1,1], b: ['aaa','aa',nil,'baaa','x',nil] })
#
# # To print nils at the bottom one can use lambda { |a| (a.nil?)[1]:[0,a.length] }
# df.sort [:b], by: {b: lambda { |a| (a.nil?)?[1]:[0,a.length] } }, handle_nils: true
#
# # =>
# #
# # a b
# # 4 -1 x
# # 1 -1 aa
# # 0 nil aaa
# # 3 nil baaa
# # 2 1 nil
# # 5 1 nil
def sort! vector_order, opts={}
raise ArgumentError, 'Required atleast one vector name' if vector_order.empty?
# To enable sorting with categorical data,
# map categories to integers preserving their order
old = convert_categorical_vectors vector_order
block = sort_prepare_block vector_order, opts
order = @index.size.times.sort(&block)
new_index = @index.reorder order
# To reverse map mapping of categorical data to integers
restore_categorical_vectors old
@data.each do |vector|
vector.reorder! order
end
self.index = new_index
self
end
# Non-destructive version of #sort!
def sort vector_order, opts={}
dup.sort! vector_order, opts
end
# Pivots a data frame on specified vectors and applies an aggregate function
# to quickly generate a summary.
#
# == Options
#
# +:index+ - Keys to group by on the pivot table row index. Pass vector names
# contained in an Array.
#
# +:vectors+ - Keys to group by on the pivot table column index. Pass vector
# names contained in an Array.
#
# +:agg+ - Function to aggregate the grouped values. Default to *:mean*. Can
# use any of the statistics functions applicable on Vectors that can be found in
# the Daru::Statistics::Vector module.
#
# +:values+ - Columns to aggregate. Will consider all numeric columns not
# specified in *:index* or *:vectors*. Optional.
#
# == Usage
#
# df = Daru::DataFrame.new({
# a: ['foo' , 'foo', 'foo', 'foo', 'foo', 'bar', 'bar', 'bar', 'bar'],
# b: ['one' , 'one', 'one', 'two', 'two', 'one', 'one', 'two', 'two'],
# c: ['small','large','large','small','small','large','small','large','small'],
# d: [1,2,2,3,3,4,5,6,7],
# e: [2,4,4,6,6,8,10,12,14]
# })
# df.pivot_table(index: [:a], vectors: [:b], agg: :sum, values: :e)
#
# #=>
# # #
# # [:e, :one] [:e, :two]
# # [:bar] 18 26
# # [:foo] 10 12
def pivot_table opts={}
raise ArgumentError, 'Specify grouping index' if Array(opts[:index]).empty?
index = opts[:index]
vectors = opts[:vectors] || []
aggregate_function = opts[:agg] || :mean
values = prepare_pivot_values index, vectors, opts
raise IndexError, 'No numeric vectors to aggregate' if values.empty?
grouped = group_by(index)
return grouped.send(aggregate_function) if vectors.empty?
super_hash = make_pivot_hash grouped, vectors, values, aggregate_function
pivot_dataframe super_hash
end
# Merge vectors from two DataFrames. In case of name collision,
# the vectors names are changed to x_1, x_2 ....
#
# @return {Daru::DataFrame}
def merge other_df # rubocop:disable Metrics/AbcSize
unless nrows == other_df.nrows
raise ArgumentError,
"Number of rows must be equal in this: #{nrows} and other: #{other_df.nrows}"
end
new_fields = (@vectors.to_a + other_df.vectors.to_a)
new_fields = ArrayHelper.recode_repeated(new_fields)
DataFrame.new({}, order: new_fields).tap do |df_new|
(0...nrows).each do |i|
df_new.add_row row[i].to_a + other_df.row[i].to_a
end
df_new.index = @index if @index == other_df.index
df_new.update
end
end
# Join 2 DataFrames with SQL style joins. Currently supports inner, left
# outer, right outer and full outer joins.
#
# @param [Daru::DataFrame] other_df Another DataFrame on which the join is
# to be performed.
# @param [Hash] opts Options Hash
# @option :how [Symbol] Can be one of :inner, :left, :right or :outer.
# @option :on [Array] The columns on which the join is to be performed.
# Column names specified here must be common to both DataFrames.
# @option :indicator [Symbol] The name of a vector to add to the resultant
# dataframe that indicates whether the record was in the left (:left_only),
# right (:right_only), or both (:both) joining dataframes.
# @return [Daru::DataFrame]
# @example Inner Join
# left = Daru::DataFrame.new({
# :id => [1,2,3,4],
# :name => ['Pirate', 'Monkey', 'Ninja', 'Spaghetti']
# })
# right = Daru::DataFrame.new({
# :id => [1,2,3,4],
# :name => ['Rutabaga', 'Pirate', 'Darth Vader', 'Ninja']
# })
# left.join(right, how: :inner, on: [:name])
# #=>
# ##
# # id_1 name id_2
# # 0 1 Pirate 2
# # 1 3 Ninja 4
def join(other_df,opts={})
Daru::Core::Merge.join(self, other_df, opts)
end
# Creates a new dataset for one to many relations
# on a dataset, based on pattern of field names.
#
# for example, you have a survey for number of children
# with this structure:
# id, name, child_name_1, child_age_1, child_name_2, child_age_2
# with
# ds.one_to_many([:id], "child_%v_%n"
# the field of first parameters will be copied verbatim
# to new dataset, and fields which responds to second
# pattern will be added one case for each different %n.
#
# @example
# cases=[
# ['1','george','red',10,'blue',20,nil,nil],
# ['2','fred','green',15,'orange',30,'white',20],
# ['3','alfred',nil,nil,nil,nil,nil,nil]
# ]
# ds=Daru::DataFrame.rows(cases, order:
# [:id, :name,
# :car_color1, :car_value1,
# :car_color2, :car_value2,
# :car_color3, :car_value3])
# ds.one_to_many([:id],'car_%v%n').to_matrix
# #=> Matrix[
# # ["red", "1", 10],
# # ["blue", "1", 20],
# # ["green", "2", 15],
# # ["orange", "2", 30],
# # ["white", "2", 20]
# # ]
def one_to_many(parent_fields, pattern)
vars, numbers = one_to_many_components(pattern)
DataFrame.new([], order: [*parent_fields, '_col_id', *vars]).tap do |ds|
each_row do |row|
verbatim = parent_fields.map { |f| [f, row[f]] }.to_h
numbers.each do |n|
generated = one_to_many_row row, n, vars, pattern
next if generated.values.all?(&:nil?)
ds.add_row(verbatim.merge(generated).merge('_col_id' => n))
end
end
ds.update
end
end
def add_vectors_by_split_recode(nm, join='-', sep=Daru::SPLIT_TOKEN)
self[nm]
.split_by_separator(sep)
.each_with_index do |(k, v), i|
v.rename "#{nm}:#{k}"
self["#{nm}#{join}#{i + 1}".to_sym] = v
end
end
# Create a sql, basen on a given Dataset
#
# == Arguments
#
# * table - String specifying name of the table that will created in SQL.
# * charset - Character set. Default is "UTF8".
#
# @example
#
# ds = Daru::DataFrame.new({
# :id => Daru::Vector.new([1,2,3,4,5]),
# :name => Daru::Vector.new(%w{Alex Peter Susan Mary John})
# })
# ds.create_sql('names')
# #=>"CREATE TABLE names (id INTEGER,\n name VARCHAR (255)) CHARACTER SET=UTF8;"
#
def create_sql(table,charset='UTF8')
sql = "CREATE TABLE #{table} ("
fields = vectors.to_a.collect do |f|
v = self[f]
f.to_s + ' ' + v.db_type
end
sql + fields.join(",\n ")+") CHARACTER SET=#{charset};"
end
# Returns the dataframe. This can be convenient when the user does not
# know whether the object is a vector or a dataframe.
# @return [self] the dataframe
def to_df
self
end
# Convert all numeric vectors to GSL::Matrix
def to_gsl
numerics_as_arrays = numeric_vectors.map { |n| self[n].to_a }
GSL::Matrix.alloc(*numerics_as_arrays.transpose)
end
# Convert all vectors of type *:numeric* into a Matrix.
def to_matrix
Matrix.columns each_vector.select(&:numeric?).map(&:to_a)
end
# Return a Nyaplot::DataFrame from the data of this DataFrame.
# :nocov:
def to_nyaplotdf
Nyaplot::DataFrame.new(to_a[0])
end
# :nocov:
# Convert all vectors of type *:numeric* and not containing nils into an NMatrix.
def to_nmatrix
each_vector.select do |vector|
vector.numeric? && !vector.include_values?(*Daru::MISSING_VALUES)
end.map(&:to_a).transpose.to_nm
end
# Converts the DataFrame into an array of hashes where key is vector name
# and value is the corresponding element. The 0th index of the array contains
# the array of hashes while the 1th index contains the indexes of each row
# of the dataframe. Each element in the index array corresponds to its row
# in the array of hashes, which has the same index.
def to_a
[each_row.map(&:to_h), @index.to_a]
end
# Convert to json. If no_index is false then the index will NOT be included
# in the JSON thus created.
def to_json no_index=true
if no_index
to_a[0].to_json
else
to_a.to_json
end
end
# Converts DataFrame to a hash (explicit) with keys as vector names and values as
# the corresponding vectors.
def to_h
@vectors
.each_with_index
.map { |vec_name, idx| [vec_name, @data[idx]] }.to_h
end
# Convert to html for IRuby.
def to_html(threshold=30)
table_thead = to_html_thead
table_tbody = to_html_tbody(threshold)
path = if index.is_a?(MultiIndex)
File.expand_path('../iruby/templates/dataframe_mi.html.erb', __FILE__)
else
File.expand_path('../iruby/templates/dataframe.html.erb', __FILE__)
end
ERB.new(File.read(path).strip).result(binding)
end
def to_html_thead
table_thead_path =
if index.is_a?(MultiIndex)
File.expand_path('../iruby/templates/dataframe_mi_thead.html.erb', __FILE__)
else
File.expand_path('../iruby/templates/dataframe_thead.html.erb', __FILE__)
end
ERB.new(File.read(table_thead_path).strip).result(binding)
end
def to_html_tbody(threshold=30)
table_tbody_path =
if index.is_a?(MultiIndex)
File.expand_path('../iruby/templates/dataframe_mi_tbody.html.erb', __FILE__)
else
File.expand_path('../iruby/templates/dataframe_tbody.html.erb', __FILE__)
end
ERB.new(File.read(table_tbody_path).strip).result(binding)
end
def to_s
"#<#{self.class}#{': ' + @name.to_s if @name}(#{nrows}x#{ncols})>"
end
# Method for updating the metadata (i.e. missing value positions) of the
# after assingment/deletion etc. are complete. This is provided so that
# time is not wasted in creating the metadata for the vector each time
# assignment/deletion of elements is done. Updating data this way is called
# lazy loading. To set or unset lazy loading, see the .lazy_update= method.
def update
@data.each(&:update) if Daru.lazy_update
end
# Rename the DataFrame.
def rename new_name
@name = new_name
self
end
alias_method :name=, :rename
# Write this DataFrame to a CSV file.
#
# == Arguments
#
# * filename - Path of CSV file where the DataFrame is to be saved.
#
# == Options
#
# * convert_comma - If set to *true*, will convert any commas in any
# of the data to full stops ('.').
# All the options accepted by CSV.read() can also be passed into this
# function.
def write_csv filename, opts={}
Daru::IO.dataframe_write_csv self, filename, opts
end
# Write this dataframe to an Excel Spreadsheet
#
# == Arguments
#
# * filename - The path of the file where the DataFrame should be written.
def write_excel filename, opts={}
Daru::IO.dataframe_write_excel self, filename, opts
end
# Insert each case of the Dataset on the selected table
#
# == Arguments
#
# * dbh - DBI database connection object.
# * query - Query string.
#
# == Usage
#
# ds = Daru::DataFrame.new({:id=>Daru::Vector.new([1,2,3]), :name=>Daru::Vector.new(["a","b","c"])})
# dbh = DBI.connect("DBI:Mysql:database:localhost", "user", "password")
# ds.write_sql(dbh,"test")
def write_sql dbh, table
Daru::IO.dataframe_write_sql self, dbh, table
end
# Use marshalling to save dataframe to a file.
def save filename
Daru::IO.save self, filename
end
def _dump(_depth)
Marshal.dump(
data: @data,
index: @index.to_a,
order: @vectors.to_a,
name: @name
)
end
def self._load data
h = Marshal.load data
Daru::DataFrame.new(h[:data],
index: h[:index],
order: h[:order],
name: h[:name])
end
# Change dtypes of vectors by supplying a hash of :vector_name => :new_dtype
#
# == Usage
# df = Daru::DataFrame.new({a: [1,2,3], b: [1,2,3], c: [1,2,3]})
# df.recast a: :nmatrix, c: :nmatrix
def recast opts={}
opts.each do |vector_name, dtype|
self[vector_name].cast(dtype: dtype)
end
end
# Transpose a DataFrame, tranposing elements and row, column indexing.
def transpose
Daru::DataFrame.new(
each_vector.map(&:to_a).transpose,
index: @vectors,
order: @index,
dtype: @dtype,
name: @name
)
end
# Pretty print in a nice table format for the command line (irb/pry/iruby)
def inspect spacing=10, threshold=15
name_part = @name ? ": #{@name} " : ''
"#<#{self.class}#{name_part}(#{nrows}x#{ncols})>\n" +
Formatters::Table.format(
each_row.lazy,
row_headers: row_headers,
headers: headers,
threshold: threshold,
spacing: spacing
)
end
# Query a DataFrame by passing a Daru::Core::Query::BoolArray object.
def where bool_array
Daru::Core::Query.df_where self, bool_array
end
def == other
self.class == other.class &&
@size == other.size &&
@index == other.index &&
@vectors == other.vectors &&
@vectors.to_a.all? { |v| self[v] == other[v] }
end
# Converts the specified non category type vectors to category type vectors
# @param [Array] names of non category type vectors to be converted
# @return [Daru::DataFrame] data frame in which specified vectors have been
# converted to category type
# @example
# df = Daru::DataFrame.new({
# a: [1, 2, 3],
# b: ['a', 'a', 'b']
# })
# df.to_category :b
# df[:b].type
# # => :category
def to_category *names
names.each { |n| self[n] = self[n].to_category }
self
end
def method_missing(name, *args, &block)
case
when name =~ /(.+)\=/
name = name[/(.+)\=/].delete('=')
name = name.to_sym unless has_vector?(name)
insert_or_modify_vector [name], args[0]
when has_vector?(name)
self[name]
when has_vector?(name.to_s)
self[name.to_s]
else
super
end
end
def respond_to_missing?(name, include_private=false)
name.to_s.end_with?('=') || has_vector?(name) || super
end
def interact_code vector_names, full
dfs = vector_names.zip(full).map do |vec_name, f|
self[vec_name].contrast_code(full: f).each.to_a
end
all_vectors = recursive_product(dfs)
Daru::DataFrame.new all_vectors,
order: all_vectors.map(&:name)
end
# Split the dataframe into many dataframes based on category vector
# @param [object] cat_name name of category vector to split the dataframe
# @return [Array] array of dataframes split by category with category vector
# used to split not included
# @example
# df = Daru::DataFrame.new({
# a: [1, 2, 3],
# b: ['a', 'a', 'b']
# })
# df.to_category :b
# df.split_by_category :b
# # => [#
# # a
# # 0 1
# # 1 2,
# # #
# # a
# # 2 3]
def split_by_category cat_name
cat_dv = self[cat_name]
raise ArgumentError, "#{cat_name} is not a category vector" unless
cat_dv.category?
cat_dv.categories.map do |cat|
where(cat_dv.eq cat)
.rename(cat)
.delete_vector cat_name
end
end
# @param indexes [Array] index(s) at which row tuples are retrieved
# @return [Array] returns array of row tuples at given index(s)
# @example Using Daru::Index
# df = Daru::DataFrame.new({
# a: [1, 2, 3],
# b: ['a', 'a', 'b']
# })
#
# df.access_row_tuples_by_indexs(1,2)
# # => [[2, "a"], [3, "b"]]
#
# df.index = Daru::Index.new([:one,:two,:three])
# df.access_row_tuples_by_indexs(:one,:three)
# # => [[1, "a"], [3, "b"]]
#
# @example Using Daru::MultiIndex
# mi_idx = Daru::MultiIndex.from_tuples [
# [:a,:one,:bar],
# [:a,:one,:baz],
# [:b,:two,:bar],
# [:a,:two,:baz],
# ]
# df_mi = Daru::DataFrame.new({
# a: 1..4,
# b: 'a'..'d'
# }, index: mi_idx )
#
# df_mi.access_row_tuples_by_indexs(:b, :two, :bar)
# # => [[3, "c"]]
# df_mi.access_row_tuples_by_indexs(:a)
# # => [[1, "a"], [2, "b"], [4, "d"]]
def access_row_tuples_by_indexs *indexes
return get_sub_dataframe(indexes, by_position: false).map_rows(&:to_a) if
@index.is_a?(Daru::MultiIndex)
positions = @index.pos(*indexes)
if positions.is_a? Numeric
row = get_rows_for([positions])
row.first.is_a?(Array) ? row : [row]
else
new_rows = get_rows_for(indexes, by_position: false)
indexes.map { |index| new_rows.map { |r| r[index] } }
end
end
# Function to use for aggregating the data.
#
# @param options [Hash] options for column, you want in resultant dataframe
#
# @return [Daru::DataFrame]
#
# @example
# df = Daru::DataFrame.new(
# {col: [:a, :b, :c, :d, :e], num: [52,12,07,17,01]})
# => #
# col num
# 0 a 52
# 1 b 12
# 2 c 7
# 3 d 17
# 4 e 1
#
# df.aggregate(num_100_times: ->(df) { (df.num*100).first })
# => #
# num_100_ti
# 0 5200
# 1 1200
# 2 700
# 3 1700
# 4 100
#
# When we have duplicate index :
#
# idx = Daru::CategoricalIndex.new [:a, :b, :a, :a, :c]
# df = Daru::DataFrame.new({num: [52,12,07,17,01]}, index: idx)
# => #
# num
# a 52
# b 12
# a 7
# a 17
# c 1
#
# df.aggregate(num: :mean)
# => #
# num
# a 25.3333333
# b 12
# c 1
#
# Note: `GroupBy` class `aggregate` method uses this `aggregate` method
# internally.
def aggregate(options={}, multi_index_level=-1)
if block_given?
positions_tuples, new_index = yield(@index) # note: use of yield is private for now
else
positions_tuples, new_index = group_index_for_aggregation(@index, multi_index_level)
end
colmn_value = aggregate_by_positions_tuples(options, positions_tuples)
Daru::DataFrame.new(colmn_value, index: new_index, order: options.keys)
end
def group_by_and_aggregate(*group_by_keys, **aggregation_map)
group_by(*group_by_keys).aggregate(aggregation_map)
end
private
# Will lazily load the plotting library being used for this dataframe
def init_plotting_library
self.plotting_library = Daru.plotting_library
end
def headers
Daru::Index.new(Array(index.name) + @vectors.to_a)
end
def row_headers
index.is_a?(MultiIndex) ? index.sparse_tuples : index.to_a
end
def convert_categorical_vectors names
names.map do |n|
next unless self[n].category?
old = [n, self[n]]
self[n] = Daru::Vector.new(self[n].to_ints)
old
end.compact
end
def restore_categorical_vectors old
old.each { |name, vector| self[name] = vector }
end
def recursive_product dfs
return dfs.first if dfs.size == 1
left = dfs.first
dfs.shift
right = recursive_product dfs
left.product(right).map do |dv1, dv2|
(dv1*dv2).rename "#{dv1.name}:#{dv2.name}"
end
end
def should_be_vector! val
return val if val.is_a?(Daru::Vector)
raise TypeError, "Every iteration must return Daru::Vector not #{val.class}"
end
def dispatch_to_axis(axis, method, *args, &block)
if %i[vector column].include?(axis)
send("#{method}_vector", *args, &block)
elsif axis == :row
send("#{method}_row", *args, &block)
else
raise ArgumentError, "Unknown axis #{axis}"
end
end
def dispatch_to_axis_pl(axis, method, *args, &block)
if %i[vector column].include?(axis)
send("#{method}_vectors", *args, &block)
elsif axis == :row
send("#{method}_rows", *args, &block)
else
raise ArgumentError, "Unknown axis #{axis}"
end
end
AXES = %i[row vector].freeze
def extract_axis names, default=:vector
if AXES.include?(names.last)
names.pop
else
default
end
end
def access_vector *names
if names.first.is_a?(Range)
dup(@vectors.subset(names.first))
elsif @vectors.is_a?(MultiIndex)
access_vector_multi_index(*names)
else
access_vector_single_index(*names)
end
end
def access_vector_multi_index *names
pos = @vectors[names]
return @data[pos] if pos.is_a?(Integer)
new_vectors = pos.map { |tuple| @data[@vectors[tuple]] }
pos = pos.drop_left_level(names.size) if names.size < @vectors.width
Daru::DataFrame.new(new_vectors, index: @index, order: pos)
end
def access_vector_single_index *names
if names.count < 2
begin
pos = @vectors.is_a?(Daru::DateTimeIndex) ? @vectors[names.first] : @vectors.pos(names.first)
rescue IndexError
raise IndexError, "Specified vector #{names.first} does not exist"
end
return @data[pos] if pos.is_a?(Numeric)
names = pos
end
new_vectors = names.map { |name| [name, @data[@vectors.pos(name)]] }.to_h
order = names.is_a?(Array) ? Daru::Index.new(names) : names
Daru::DataFrame.new(new_vectors, order: order,
index: @index, name: @name)
end
def access_row *indexes
positions = @index.pos(*indexes)
if positions.is_a? Numeric
row = get_rows_for([positions])
Daru::Vector.new row, index: @vectors, name: indexes.first
else
new_rows = get_rows_for(indexes, by_position: false)
Daru::DataFrame.new new_rows, index: @index.subset(*indexes), order: @vectors
end
end
# @param keys [Array] can be an array of positions (if by_position is true) or indexes (if by_position if false)
# because of coercion by Daru::Vector#at and Daru::Vector#[], can return either an Array of
# values (representing a row) or an array of Vectors (that can be seen as rows)
def get_rows_for(keys, by_position: true)
raise unless keys.is_a?(Array)
if by_position
pos = keys
@data.map { |vector| vector.at(*pos) }
else
# TODO: for now (2018-07-27), it is different than using
# get_rows_for(@index.pos(*keys))
# because Daru::Vector#at and Daru::Vector#[] don't handle Daru::MultiIndex the same way
indexes = keys
@data.map { |vec| vec[*indexes] }
end
end
def insert_or_modify_vector name, vector
name = name[0] unless @vectors.is_a?(MultiIndex)
if @index.empty?
insert_vector_in_empty name, vector
else
vec = prepare_for_insert name, vector
assign_or_add_vector name, vec
end
end
def assign_or_add_vector name, v
# FIXME: fix this jugaad. need to make changes in Indexing itself.
begin
pos = @vectors[name]
rescue IndexError
pos = name
end
case
when pos.is_a?(Daru::Index)
assign_multiple_vectors pos, v
when pos == name &&
(@vectors.include?(name) || (pos.is_a?(Integer) && pos < @data.size))
@data[pos] = v
else
assign_or_add_vector_rough name, v
end
end
def assign_multiple_vectors pos, v
pos.each do |p|
@data[@vectors[p]] = v
end
end
def assign_or_add_vector_rough name, v
@vectors |= [name] unless @vectors.include?(name)
@data[@vectors[name]] = v
end
def insert_vector_in_empty name, vector
vec = Vector.coerce(vector.to_a, name: coerce_name(name))
@index = vec.index
assign_or_add_vector name, vec
set_size
@data.map! { |v| v.empty? ? v.reindex(@index) : v }
end
def prepare_for_insert name, arg
if arg.is_a? Daru::Vector
prepare_vector_for_insert name, arg
elsif arg.respond_to?(:to_a)
prepare_enum_for_insert name, arg
else
prepare_value_for_insert name, arg
end
end
def prepare_vector_for_insert name, vector
# so that index-by-index assignment is avoided when possible.
return vector.dup if vector.index == @index
Daru::Vector.new([], name: coerce_name(name), index: @index).tap { |v|
@index.each do |idx|
v[idx] = vector.index.include?(idx) ? vector[idx] : nil
end
}
end
def prepare_enum_for_insert name, enum
if @size != enum.size
raise "Specified vector of length #{enum.size} cannot be inserted in DataFrame of size #{@size}"
end
Daru::Vector.new(enum, name: coerce_name(name), index: @index)
end
def prepare_value_for_insert name, value
Daru::Vector.new(Array(value) * @size, name: coerce_name(name), index: @index)
end
def insert_or_modify_row indexes, vector
vector = coerce_vector vector
raise SizeError, 'Vector length should match row length' if
vector.size != @vectors.size
@data.each_with_index do |vec, pos|
vec.send(:set, indexes, vector.at(pos))
end
@index = @data[0].index
set_size
end
def create_empty_vectors(vectors, index)
@vectors = Index.coerce vectors
@index = Index.coerce index
@data = @vectors.map do |name|
Daru::Vector.new([], name: coerce_name(name), index: @index)
end
end
def validate_labels
if @vectors && @vectors.size != @data.size
raise IndexError, "Expected equal number of vector names (#{@vectors.size}) " \
"for number of vectors (#{@data.size})."
end
return unless @index && @data[0] && @index.size != @data[0].size
raise IndexError, 'Expected number of indexes same as number of rows'
end
def validate_vector_sizes
@data.each do |vector|
raise IndexError, 'Expected vectors with equal length' if vector.size != @size
end
end
def validate
validate_labels
validate_vector_sizes
end
def set_size
@size = @index.size
end
def named_index_for index
if @index.include? index
index
elsif @index.key index
@index.key index
else
raise IndexError, "Specified index #{index} does not exist."
end
end
def create_vectors_index_with vectors, source
vectors = source.keys if vectors.nil?
@vectors =
if vectors.is_a?(Index) || vectors.is_a?(MultiIndex)
vectors
else
Daru::Index.new((vectors + (source.keys - vectors)).uniq)
end
end
def all_vectors_have_equal_indexes? source
idx = source.values[0].index
source.values.all? { |vector| idx == vector.index }
end
def coerce_name potential_name
potential_name.is_a?(Array) ? potential_name.join : potential_name
end
def initialize_from_array source, vectors, index, opts
raise ArgumentError, 'All objects in data source should be same class' \
unless source.map(&:class).uniq.size == 1
case source.first
when Array
vectors ||= (0..source.size-1).to_a
initialize_from_array_of_arrays source, vectors, index, opts
when Vector
vectors ||= (0..source.size-1).to_a
initialize_from_array_of_vectors source, vectors, index, opts
when Hash
initialize_from_array_of_hashes source, vectors, index, opts
else
raise ArgumentError, "Can't create DataFrame from #{source}"
end
end
def initialize_from_array_of_arrays source, vectors, index, _opts
if source.size != vectors.size
raise ArgumentError, "Number of vectors (#{vectors.size}) should " \
"equal order size (#{source.size})"
end
@index = Index.coerce(index || source[0].size)
@vectors = Index.coerce(vectors)
update_data source, vectors
end
def initialize_from_array_of_vectors source, vectors, index, opts
clone = opts[:clone] != false
hsh = vectors.each_with_index.map do |name, idx|
[name, source[idx]]
end.to_h
initialize(hsh, index: index, order: vectors, name: @name, clone: clone)
end
def initialize_from_array_of_hashes source, vectors, index, _opts
names =
if vectors.nil?
source[0].keys
else
(vectors + source[0].keys).uniq
end
@vectors = Daru::Index.new(names)
@index = Daru::Index.new(index || source.size)
@data = @vectors.map do |name|
v = source.map { |h| h.fetch(name) { h[name.to_s] } }
Daru::Vector.new(v, name: coerce_name(name), index: @index)
end
end
def initialize_from_hash source, vectors, index, opts
create_vectors_index_with vectors, source
if ArrayHelper.array_of?(source.values, Vector)
initialize_from_hash_with_vectors source, index, opts
else
initialize_from_hash_with_arrays source, index, opts
end
end
def initialize_from_hash_with_vectors source, index, opts
vectors_have_same_index = all_vectors_have_equal_indexes?(source)
clone = opts[:clone] != false
clone = true unless index || vectors_have_same_index
@index = deduce_index index, source, vectors_have_same_index
if clone
@data = clone_vectors source, vectors_have_same_index
else
@data.concat source.values
end
end
def deduce_index index, source, vectors_have_same_index
if !index.nil?
Index.coerce index
elsif vectors_have_same_index
source.values[0].index.dup
else
all_indexes = source
.values.map { |v| v.index.to_a }
.flatten.uniq.sort # sort only if missing indexes detected
Daru::Index.new all_indexes
end
end
def clone_vectors source, vectors_have_same_index
@vectors.map do |vector|
# avoids matching indexes of vectors if all the supplied vectors
# have the same index.
if vectors_have_same_index
source[vector].dup
else
Daru::Vector.new([], name: vector, index: @index).tap do |v|
@index.each do |idx|
v[idx] = source[vector].index.include?(idx) ? source[vector][idx] : nil
end
end
end
end
end
def initialize_from_hash_with_arrays source, index, _opts
@index = Index.coerce(index || source.values[0].size)
@vectors.each do |name|
@data << Daru::Vector.new(source[name].dup, name: coerce_name(name), index: @index)
end
end
def sort_build_row vector_locs, by_blocks, ascending, handle_nils, r1, r2 # rubocop:disable Metrics/ParameterLists
# Create an array to be used for comparison of two rows in sorting
vector_locs
.zip(by_blocks, ascending, handle_nils)
.map do |vector_loc, by, asc, handle_nil|
value = @data[vector_loc].data[asc ? r1 : r2]
value = by.call(value) rescue nil if by
sort_handle_nils value, asc, handle_nil || !by
end
end
def sort_handle_nils value, asc, handle_nil
case
when !handle_nil
value
when asc
[value.nil? ? 0 : 1, value]
else
[value.nil? ? 1 : 0, value]
end
end
def sort_coerce_boolean opts, symbol, default, size
val = opts[symbol]
case val
when true, false
Array.new(size, val)
when nil
Array.new(size, default)
when Array
raise ArgumentError, "Specify same number of vector names and #{symbol}" if
size != val.size
val
else
raise ArgumentError, "Can't coerce #{symbol} from #{val.class} to boolean option"
end
end
def sort_prepare_block vector_order, opts
ascending = sort_coerce_boolean opts, :ascending, true, vector_order.size
handle_nils = sort_coerce_boolean opts, :handle_nils, false, vector_order.size
by_blocks = vector_order.map { |v| (opts[:by] || {})[v] }
vector_locs = vector_order.map { |v| @vectors[v] }
lambda do |index1, index2|
# Build left and right array to compare two rows
left = sort_build_row vector_locs, by_blocks, ascending, handle_nils, index1, index2
right = sort_build_row vector_locs, by_blocks, ascending, handle_nils, index2, index1
# Resolve conflict by Index if all attributes are same
left << index1
right << index2
left <=> right
end
end
def verify_error_message row, test, id, i
description, fields, = test
values =
if fields.empty?
''
else
' (' + fields.collect { |k| "#{k}=#{row[k]}" }.join(', ') + ')'
end
"#{i+1} [#{row[id]}]: #{description}#{values}"
end
def prepare_pivot_values index, vectors, opts
case opts[:values]
when nil # values not specified at all.
(@vectors.to_a - (index | vectors)) & numeric_vector_names
when Array # multiple values specified.
opts[:values]
else # single value specified.
[opts[:values]]
end
end
def make_pivot_hash grouped, vectors, values, aggregate_function
grouped.groups.map { |n, _| [n, {}] }.to_h.tap do |super_hash|
values.each do |value|
grouped.groups.each do |group_name, row_numbers|
row_numbers.each do |num|
arry = [value, *vectors.map { |v| self[v][num] }]
sub_hash = super_hash[group_name]
sub_hash[arry] ||= []
sub_hash[arry] << self[value][num]
end
end
end
setup_pivot_aggregates super_hash, aggregate_function
end
end
def setup_pivot_aggregates super_hash, aggregate_function
super_hash.each_value do |sub_hash|
sub_hash.each do |group_name, aggregates|
sub_hash[group_name] = Daru::Vector.new(aggregates).send(aggregate_function)
end
end
end
def pivot_dataframe super_hash
df_index = Daru::MultiIndex.from_tuples super_hash.keys
df_vectors = Daru::MultiIndex.from_tuples super_hash.values.flat_map(&:keys).uniq
Daru::DataFrame.new({}, index: df_index, order: df_vectors).tap do |pivoted_dataframe|
super_hash.each do |row_index, sub_h|
sub_h.each do |vector_index, val|
pivoted_dataframe[vector_index][row_index] = val
end
end
end
end
def one_to_many_components pattern
re = Regexp.new pattern.gsub('%v','(.+?)').gsub('%n','(\\d+?)')
vars, numbers =
@vectors
.map { |v| v.scan(re) }
.reject(&:empty?).flatten(1).transpose
[vars.uniq, numbers.map(&:to_i).sort.uniq]
end
def one_to_many_row row, number, vars, pattern
vars
.map { |v|
name = pattern.sub('%v', v).sub('%n', number.to_s)
[v, row[name]]
}.to_h
end
# Raises IndexError when one of the positions is not a valid position
def validate_positions *positions, size
positions.each do |pos|
raise IndexError, "#{pos} is not a valid position." if pos >= size
end
end
# Accepts hash, enumerable and vector and align it properly so it can be added
def coerce_vector vector
case vector
when Daru::Vector
vector.reindex @vectors
when Hash
Daru::Vector.new(vector).reindex @vectors
else
Daru::Vector.new vector
end
end
def update_data source, vectors
@data = @vectors.each_with_index.map do |_vec, idx|
Daru::Vector.new(source[idx], index: @index, name: vectors[idx])
end
end
def aggregate_by_positions_tuples(options, positions_tuples)
agg_over_vectors_only, options = cast_aggregation_options(options)
if agg_over_vectors_only
options.map do |vect_name, method|
vect = self[vect_name]
positions_tuples.map do |positions|
vect.apply_method_on_sub_vector(method, keys: positions)
end
end
else
methods = options.values
# note: because we aggregate over rows, we don't have to re-get sub-dfs for each method (which is expensive)
rows = positions_tuples.map do |positions|
apply_method_on_sub_df(methods, keys: positions)
end
rows.transpose
end
end
# convert operations over sub-vectors to operations over sub-dfs when it improves perf
# note: we don't always "cast" because aggregation over a single vector / a few vector is faster
# than aggregation over (sub-)dfs
def cast_aggregation_options(options)
vects, non_vects = options.keys.partition { |k| @vectors.include?(k) }
over_vectors = true
if non_vects.any?
options = options.clone
vects.each do |name|
proc_on_vect = options[name].to_proc
options[name] = ->(sub_df) { proc_on_vect.call(sub_df[name]) }
end
over_vectors = false
end
[over_vectors, options]
end
def group_index_for_aggregation(index, multi_index_level=-1)
case index
when Daru::MultiIndex
groups_by_pos = Daru::Core::GroupBy.get_positions_group_for_aggregation(index, multi_index_level)
new_index = Daru::MultiIndex.from_tuples(groups_by_pos.keys).coerce_index
pos_tuples = groups_by_pos.values
when Daru::Index, Daru::CategoricalIndex
new_index = Array(index).uniq
pos_tuples = new_index.map { |idx| [*index.pos(idx)] }
else raise
end
[pos_tuples, new_index]
end
# coerce ranges, integers and array in appropriate ways
def coerce_positions *positions, size
if positions.size == 1
case positions.first
when Integer
positions.first
when Range
size.times.to_a[positions.first]
else
raise ArgumentError, 'Unknown position type.'
end
else
positions
end
end
end
end
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