require 'rubygems'
require 'RMagick'
require File.dirname(__FILE__) + '/deprecated'
##
# = Gruff. Graphs.
#
# Author:: Geoffrey Grosenbach boss@topfunky.com
#
# Originally Created:: October 23, 2005
#
# Extra thanks to Tim Hunter for writing RMagick, and also contributions by
# Jarkko Laine, Mike Perham, Andreas Schwarz, Alun Eyre, Guillaume Theoret,
# David Stokar, Paul Rogers, Dave Woodward, Frank Oxener, Kevin Clark, Cies
# Breijs, Richard Cowin, and a cast of thousands.
#
# See Gruff::Base#theme= for setting themes.
module Gruff
# This is the version of Gruff you are using.
VERSION = '0.3.6'
class Base
include Magick
include Deprecated
# Draw extra lines showing where the margins and text centers are
DEBUG = false
# Used for navigating the array of data to plot
DATA_LABEL_INDEX = 0
DATA_VALUES_INDEX = 1
DATA_COLOR_INDEX = 2
# Space around text elements. Mostly used for vertical spacing
LEGEND_MARGIN = TITLE_MARGIN = LABEL_MARGIN = 10.0
DEFAULT_TARGET_WIDTH = 800
# Blank space above the graph
attr_accessor :top_margin
# Blank space below the graph
attr_accessor :bottom_margin
# Blank space to the right of the graph
attr_accessor :right_margin
# Blank space to the left of the graph
attr_accessor :left_margin
# A hash of names for the individual columns, where the key is the array
# index for the column this label represents.
#
# Not all columns need to be named.
#
# Example: 0 => 2005, 3 => 2006, 5 => 2007, 7 => 2008
attr_accessor :labels
# Used internally for spacing.
#
# By default, labels are centered over the point they represent.
attr_accessor :center_labels_over_point
# Used internally for horizontal graph types.
attr_accessor :has_left_labels
# A label for the bottom of the graph
attr_accessor :x_axis_label
# A label for the left side of the graph
attr_accessor :y_axis_label
# attr_accessor :x_axis_increment
# Manually set increment of the horizontal marking lines
attr_accessor :y_axis_increment
# Get or set the list of colors that will be used to draw the bars or lines.
attr_accessor :colors
# The large title of the graph displayed at the top
attr_accessor :title
# Font used for titles, labels, etc. Works best if you provide the full
# path to the TTF font file. RMagick must be built with the Freetype
# libraries for this to work properly.
#
# Tries to find Bitstream Vera (Vera.ttf) in the location specified by
# ENV['MAGICK_FONT_PATH']. Uses default RMagick font otherwise.
#
# The font= method below fulfills the role of the writer, so we only need
# a reader here.
attr_reader :font
attr_accessor :font_color
# Prevent drawing of line markers
attr_accessor :hide_line_markers
# Prevent drawing of the legend
attr_accessor :hide_legend
# Prevent drawing of the title
attr_accessor :hide_title
# Prevent drawing of line numbers
attr_accessor :hide_line_numbers
# Message shown when there is no data. Fits up to 20 characters. Defaults
# to "No Data."
attr_accessor :no_data_message
# The font size of the large title at the top of the graph
attr_accessor :title_font_size
# Optionally set the size of the font. Based on an 800x600px graph.
# Default is 20.
#
# Will be scaled down if graph is smaller than 800px wide.
attr_accessor :legend_font_size
# The font size of the labels around the graph
attr_accessor :marker_font_size
# The color of the auxiliary lines
attr_accessor :marker_color
# The number of horizontal lines shown for reference
attr_accessor :marker_count
# You can manually set a minimum value instead of having the values
# guessed for you.
#
# Set it after you have given all your data to the graph object.
attr_accessor :minimum_value
# You can manually set a maximum value, such as a percentage-based graph
# that always goes to 100.
#
# If you use this, you must set it after you have given all your data to
# the graph object.
attr_accessor :maximum_value
# Set to false if you don't want the data to be sorted with largest avg
# values at the back.
attr_accessor :sort
# Experimental
attr_accessor :additional_line_values
# Experimental
attr_accessor :stacked
# Optionally set the size of the colored box by each item in the legend.
# Default is 20.0
#
# Will be scaled down if graph is smaller than 800px wide.
attr_accessor :legend_box_size
# If one numerical argument is given, the graph is drawn at 4/3 ratio
# according to the given width (800 results in 800x600, 400 gives 400x300,
# etc.).
#
# Or, send a geometry string for other ratios ('800x400', '400x225').
#
# Looks for Bitstream Vera as the default font. Expects an environment var
# of MAGICK_FONT_PATH to be set. (Uses RMagick's default font otherwise.)
def initialize(target_width=DEFAULT_TARGET_WIDTH)
@top_margin = @bottom_margin = @left_margin = @right_margin = 20.0
if not Numeric === target_width
geometric_width, geometric_height = target_width.split('x')
@columns = geometric_width.to_f
@rows = geometric_height.to_f
else
@columns = target_width.to_f
@rows = target_width.to_f * 0.75
end
initialize_ivars
reset_themes
theme_keynote
end
# Set instance variables for this object.
#
# Subclasses can override this, call super, then set values separately.
#
# This makes it possible to set defaults in a subclass but still allow
# developers to change this values in their program.
def initialize_ivars
# Internal for calculations
@raw_columns = 800.0
@raw_rows = 800.0 * (@rows/@columns)
@column_count = 0
@marker_count = nil
@maximum_value = @minimum_value = nil
@has_data = false
@data = Array.new
@labels = Hash.new
@labels_seen = Hash.new
@sort = true
@title = nil
@scale = @columns / @raw_columns
vera_font_path = File.expand_path('Vera.ttf', ENV['MAGICK_FONT_PATH'])
@font = File.exists?(vera_font_path) ? vera_font_path : nil
@marker_font_size = 21.0
@legend_font_size = 20.0
@title_font_size = 36.0
@legend_box_size = 20.0
@no_data_message = "No Data"
@hide_line_markers = @hide_legend = @hide_title = @hide_line_numbers = false
@center_labels_over_point = true
@has_left_labels = false
@additional_line_values = []
@additional_line_colors = []
@theme_options = {}
@x_axis_label = @y_axis_label = nil
@y_axis_increment = nil
@stacked = nil
@norm_data = nil
end
# Sets the top, bottom, left and right margins to +margin+.
def margins=(margin)
@top_margin = @left_margin = @right_margin = @bottom_margin = margin
end
# Sets the font for graph text to the font at +font_path+.
def font=(font_path)
@font = font_path
@d.font = @font
end
# Add a color to the list of available colors for lines.
#
# Example:
# add_color('#c0e9d3')
def add_color(colorname)
@colors << colorname
end
# Replace the entire color list with a new array of colors. Also
# aliased as the colors= setter method.
#
# If you specify fewer colors than the number of datasets you intend
# to draw, 'increment_color' will cycle through the array, reusing
# colors as needed.
#
# Note that (as with the 'theme' method), you should set up your color
# list before you send your data (via the 'data' method). Calls to the
# 'data' method made prior to this call will use whatever color scheme
# was in place at the time data was called.
#
# Example:
# replace_colors ['#cc99cc', '#d9e043', '#34d8a2']
def replace_colors(color_list=[])
@colors = color_list
@color_index = 0
end
# You can set a theme manually. Assign a hash to this method before you
# send your data.
#
# graph.theme = {
# :colors => %w(orange purple green white red),
# :marker_color => 'blue',
# :background_colors => %w(black grey)
# }
#
# :background_image => 'squirrel.png' is also possible.
#
# (Or hopefully something better looking than that.)
#
def theme=(options)
reset_themes()
defaults = {
:colors => ['black', 'white'],
:additional_line_colors => [],
:marker_color => 'white',
:font_color => 'black',
:background_colors => nil,
:background_image => nil
}
@theme_options = defaults.merge options
@colors = @theme_options[:colors]
@marker_color = @theme_options[:marker_color]
@font_color = @theme_options[:font_color] || @marker_color
@additional_line_colors = @theme_options[:additional_line_colors]
render_background
end
# A color scheme similar to the popular presentation software.
def theme_keynote
# Colors
@blue = '#6886B4'
@yellow = '#FDD84E'
@green = '#72AE6E'
@red = '#D1695E'
@purple = '#8A6EAF'
@orange = '#EFAA43'
@white = 'white'
@colors = [@yellow, @blue, @green, @red, @purple, @orange, @white]
self.theme = {
:colors => @colors,
:marker_color => 'white',
:font_color => 'white',
:background_colors => ['black', '#4a465a']
}
end
# A color scheme plucked from the colors on the popular usability blog.
def theme_37signals
# Colors
@green = '#339933'
@purple = '#cc99cc'
@blue = '#336699'
@yellow = '#FFF804'
@red = '#ff0000'
@orange = '#cf5910'
@black = 'black'
@colors = [@yellow, @blue, @green, @red, @purple, @orange, @black]
self.theme = {
:colors => @colors,
:marker_color => 'black',
:font_color => 'black',
:background_colors => ['#d1edf5', 'white']
}
end
# A color scheme from the colors used on the 2005 Rails keynote
# presentation at RubyConf.
def theme_rails_keynote
# Colors
@green = '#00ff00'
@grey = '#333333'
@orange = '#ff5d00'
@red = '#f61100'
@white = 'white'
@light_grey = '#999999'
@black = 'black'
@colors = [@green, @grey, @orange, @red, @white, @light_grey, @black]
self.theme = {
:colors => @colors,
:marker_color => 'white',
:font_color => 'white',
:background_colors => ['#0083a3', '#0083a3']
}
end
# A color scheme similar to that used on the popular podcast site.
def theme_odeo
# Colors
@grey = '#202020'
@white = 'white'
@dark_pink = '#a21764'
@green = '#8ab438'
@light_grey = '#999999'
@dark_blue = '#3a5b87'
@black = 'black'
@colors = [@grey, @white, @dark_blue, @dark_pink, @green, @light_grey, @black]
self.theme = {
:colors => @colors,
:marker_color => 'white',
:font_color => 'white',
:background_colors => ['#ff47a4', '#ff1f81']
}
end
# A pastel theme
def theme_pastel
# Colors
@colors = [
'#a9dada', # blue
'#aedaa9', # green
'#daaea9', # peach
'#dadaa9', # yellow
'#a9a9da', # dk purple
'#daaeda', # purple
'#dadada' # grey
]
self.theme = {
:colors => @colors,
:marker_color => '#aea9a9', # Grey
:font_color => 'black',
:background_colors => 'white'
}
end
# A greyscale theme
def theme_greyscale
# Colors
@colors = [
'#282828', #
'#383838', #
'#686868', #
'#989898', #
'#c8c8c8', #
'#e8e8e8', #
]
self.theme = {
:colors => @colors,
:marker_color => '#aea9a9', # Grey
:font_color => 'black',
:background_colors => 'white'
}
end
# Parameters are an array where the first element is the name of the dataset
# and the value is an array of values to plot.
#
# Can be called multiple times with different datasets for a multi-valued
# graph.
#
# If the color argument is nil, the next color from the default theme will
# be used.
#
# NOTE: If you want to use a preset theme, you must set it before calling
# data().
#
# Example:
# data("Bart S.", [95, 45, 78, 89, 88, 76], '#ffcc00')
def data(name, data_points=[], color=nil)
data_points = Array(data_points) # make sure it's an array
@data << [name, data_points, (color || increment_color)]
# Set column count if this is larger than previous counts
@column_count = (data_points.length > @column_count) ? data_points.length : @column_count
# Pre-normalize
data_points.each_with_index do |data_point, index|
next if data_point.nil?
# Setup max/min so spread starts at the low end of the data points
if @maximum_value.nil? && @minimum_value.nil?
@maximum_value = @minimum_value = data_point
end
# TODO Doesn't work with stacked bar graphs
# Original: @maximum_value = larger_than_max?(data_point, index) ? max(data_point, index) : @maximum_value
@maximum_value = larger_than_max?(data_point) ? data_point : @maximum_value
@has_data = true if @maximum_value >= 0
@minimum_value = less_than_min?(data_point) ? data_point : @minimum_value
@has_data = true if @minimum_value < 0
end
end
# Writes the graph to a file. Defaults to 'graph.png'
#
# Example:
# write('graphs/my_pretty_graph.png')
def write(filename="graph.png")
draw()
@base_image.write(filename)
end
# Return the graph as a rendered binary blob.
def to_blob(fileformat='PNG')
draw()
return @base_image.to_blob do
self.format = fileformat
end
end
protected
# Overridden by subclasses to do the actual plotting of the graph.
#
# Subclasses should start by calling super() for this method.
def draw
make_stacked if @stacked
setup_drawing
debug {
# Outer margin
@d.rectangle( @left_margin, @top_margin,
@raw_columns - @right_margin, @raw_rows - @bottom_margin)
# Graph area box
@d.rectangle( @graph_left, @graph_top, @graph_right, @graph_bottom)
}
end
# Calculates size of drawable area and draws the decorations.
#
# * line markers
# * legend
# * title
def setup_drawing
# Maybe should be done in one of the following functions for more granularity.
unless @has_data
draw_no_data()
return
end
normalize()
setup_graph_measurements()
sort_norm_data() if @sort # Sort norm_data with avg largest values set first (for display)
draw_legend()
draw_line_markers()
draw_axis_labels()
draw_title
end
# Make copy of data with values scaled between 0-100
def normalize(force=false)
if @norm_data.nil? || force
@norm_data = []
return unless @has_data
calculate_spread
@data.each do |data_row|
norm_data_points = []
data_row[DATA_VALUES_INDEX].each do |data_point|
if data_point.nil?
norm_data_points << nil
else
norm_data_points << ((data_point.to_f - @minimum_value.to_f ) / @spread)
end
end
@norm_data << [data_row[DATA_LABEL_INDEX], norm_data_points, data_row[DATA_COLOR_INDEX]]
end
end
end
def calculate_spread # :nodoc:
@spread = @maximum_value.to_f - @minimum_value.to_f
@spread = @spread > 0 ? @spread : 1
end
##
# Calculates size of drawable area, general font dimensions, etc.
def setup_graph_measurements
@marker_caps_height = @hide_line_markers ? 0 :
calculate_caps_height(@marker_font_size)
@title_caps_height = @hide_title ? 0 :
calculate_caps_height(@title_font_size)
@legend_caps_height = @hide_legend ? 0 :
calculate_caps_height(@legend_font_size)
if @hide_line_markers
(@graph_left,
@graph_right_margin,
@graph_bottom_margin) = [@left_margin, @right_margin, @bottom_margin]
else
longest_left_label_width = 0
if @has_left_labels
longest_left_label_width = calculate_width(@marker_font_size,
labels.values.inject('') { |value, memo| (value.to_s.length > memo.to_s.length) ? value : memo }) * 1.25
else
longest_left_label_width = calculate_width(@marker_font_size,
label(@maximum_value.to_f))
end
# Shift graph if left line numbers are hidden
line_number_width = @hide_line_numbers && !@has_left_labels ?
0.0 :
(longest_left_label_width + LABEL_MARGIN * 2)
@graph_left = @left_margin +
line_number_width +
(@y_axis_label.nil? ? 0.0 : @marker_caps_height + LABEL_MARGIN * 2)
# Make space for half the width of the rightmost column label.
# Might be greater than the number of columns if between-style bar markers are used.
last_label = @labels.keys.sort.last.to_i
extra_room_for_long_label = (last_label >= (@column_count-1) && @center_labels_over_point) ?
calculate_width(@marker_font_size, @labels[last_label]) / 2.0 :
0
@graph_right_margin = @right_margin + extra_room_for_long_label
@graph_bottom_margin = @bottom_margin +
@marker_caps_height + LABEL_MARGIN
end
@graph_right = @raw_columns - @graph_right_margin
@graph_width = @raw_columns - @graph_left - @graph_right_margin
# When @hide title, leave a TITLE_MARGIN space for aesthetics.
# Same with @hide_legend
@graph_top = @top_margin +
(@hide_title ? TITLE_MARGIN : @title_caps_height + TITLE_MARGIN * 2) +
(@hide_legend ? LEGEND_MARGIN : @legend_caps_height + LEGEND_MARGIN * 2)
x_axis_label_height = @x_axis_label.nil? ? 0.0 :
@marker_caps_height + LABEL_MARGIN
@graph_bottom = @raw_rows - @graph_bottom_margin - x_axis_label_height
@graph_height = @graph_bottom - @graph_top
end
# Draw the optional labels for the x axis and y axis.
def draw_axis_labels
unless @x_axis_label.nil?
# X Axis
# Centered vertically and horizontally by setting the
# height to 1.0 and the width to the width of the graph.
x_axis_label_y_coordinate = @graph_bottom + LABEL_MARGIN * 2 + @marker_caps_height
# TODO Center between graph area
@d.fill = @font_color
@d.font = @font if @font
@d.stroke('transparent')
@d.pointsize = scale_fontsize(@marker_font_size)
@d.gravity = NorthGravity
@d = @d.annotate_scaled( @base_image,
@raw_columns, 1.0,
0.0, x_axis_label_y_coordinate,
@x_axis_label, @scale)
debug { @d.line 0.0, x_axis_label_y_coordinate, @raw_columns, x_axis_label_y_coordinate }
end
unless @y_axis_label.nil?
# Y Axis, rotated vertically
@d.rotation = 90.0
@d.gravity = CenterGravity
@d = @d.annotate_scaled( @base_image,
1.0, @raw_rows,
@left_margin + @marker_caps_height / 2.0, 0.0,
@y_axis_label, @scale)
@d.rotation = -90.0
end
end
# Draws horizontal background lines and labels
def draw_line_markers
return if @hide_line_markers
@d = @d.stroke_antialias false
if @y_axis_increment.nil?
# Try to use a number of horizontal lines that will come out even.
#
# TODO Do the same for larger numbers...100, 75, 50, 25
if @marker_count.nil?
(3..7).each do |lines|
if @spread % lines == 0.0
@marker_count = lines
break
end
end
@marker_count ||= 4
end
@increment = (@spread > 0) ? significant(@spread / @marker_count) : 1
else
# TODO Make this work for negative values
@maximum_value = [@maximum_value.ceil, @y_axis_increment].max
@minimum_value = @minimum_value.floor
calculate_spread
normalize(true)
@marker_count = (@spread / @y_axis_increment).to_i
@increment = @y_axis_increment
end
@increment_scaled = @graph_height.to_f / (@spread / @increment)
# Draw horizontal line markers and annotate with numbers
(0..@marker_count).each do |index|
y = @graph_top + @graph_height - index.to_f * @increment_scaled
@d = @d.fill(@marker_color)
@d = @d.line(@graph_left, y, @graph_right, y)
marker_label = index * @increment + @minimum_value.to_f
unless @hide_line_numbers
@d.fill = @font_color
@d.font = @font if @font
@d.stroke('transparent')
@d.pointsize = scale_fontsize(@marker_font_size)
@d.gravity = EastGravity
# Vertically center with 1.0 for the height
@d = @d.annotate_scaled( @base_image,
@graph_left - LABEL_MARGIN, 1.0,
0.0, y,
label(marker_label), @scale)
end
end
# # Submitted by a contibutor...the utility escapes me
# i = 0
# @additional_line_values.each do |value|
# @increment_scaled = @graph_height.to_f / (@maximum_value.to_f / value)
#
# y = @graph_top + @graph_height - @increment_scaled
#
# @d = @d.stroke(@additional_line_colors[i])
# @d = @d.line(@graph_left, y, @graph_right, y)
#
#
# @d.fill = @additional_line_colors[i]
# @d.font = @font if @font
# @d.stroke('transparent')
# @d.pointsize = scale_fontsize(@marker_font_size)
# @d.gravity = EastGravity
# @d = @d.annotate_scaled( @base_image,
# 100, 20,
# -10, y - (@marker_font_size/2.0),
# "", @scale)
# i += 1
# end
@d = @d.stroke_antialias true
end
##
# Return the sum of values in an array.
#
# Duplicated to not conflict with active_support in Rails.
def sum(arr)
arr.inject(0) { |i, m| m + i }
end
##
# Return a calculation of center
def center(size)
(@raw_columns - size) / 2
end
##
# Draws a legend with the names of the datasets matched
# to the colors used to draw them.
def draw_legend
return if @hide_legend
@legend_labels = @data.collect {|item| item[DATA_LABEL_INDEX] }
legend_square_width = @legend_box_size # small square with color of this item
# May fix legend drawing problem at small sizes
@d.font = @font if @font
@d.pointsize = @legend_font_size
label_widths = [[]] # Used to calculate line wrap
@legend_labels.each do |label|
metrics = @d.get_type_metrics(@base_image, label.to_s)
label_width = metrics.width + legend_square_width * 2.7
label_widths.last.push label_width
if sum(label_widths.last) > (@raw_columns * 0.9)
label_widths.push [label_widths.last.pop]
end
end
current_x_offset = center(sum(label_widths.first))
current_y_offset = @hide_title ?
@top_margin + LEGEND_MARGIN :
@top_margin + TITLE_MARGIN + @title_caps_height + LEGEND_MARGIN
@legend_labels.each_with_index do |legend_label, index|
# Draw label
@d.fill = @font_color
@d.font = @font if @font
@d.pointsize = scale_fontsize(@legend_font_size)
@d.stroke('transparent')
@d.font_weight = NormalWeight
@d.gravity = WestGravity
@d = @d.annotate_scaled( @base_image,
@raw_columns, 1.0,
current_x_offset + (legend_square_width * 1.7), current_y_offset,
legend_label.to_s, @scale)
# Now draw box with color of this dataset
@d = @d.stroke('transparent')
@d = @d.fill @data[index][DATA_COLOR_INDEX]
@d = @d.rectangle(current_x_offset,
current_y_offset - legend_square_width / 2.0,
current_x_offset + legend_square_width,
current_y_offset + legend_square_width / 2.0)
@d.pointsize = @legend_font_size
metrics = @d.get_type_metrics(@base_image, legend_label.to_s)
current_string_offset = metrics.width + (legend_square_width * 2.7)
# Handle wrapping
label_widths.first.shift
if label_widths.first.empty?
debug { @d.line 0.0, current_y_offset, @raw_columns, current_y_offset }
label_widths.shift
current_x_offset = center(sum(label_widths.first)) unless label_widths.empty?
line_height = [@legend_caps_height, legend_square_width].max + LEGEND_MARGIN
if label_widths.length > 0
# Wrap to next line and shrink available graph dimensions
current_y_offset += line_height
@graph_top += line_height
@graph_height = @graph_bottom - @graph_top
end
else
current_x_offset += current_string_offset
end
end
@color_index = 0
end
# Draws a title on the graph.
def draw_title
return if (@hide_title || @title.nil?)
@d.fill = @font_color
@d.font = @font if @font
@d.stroke('transparent')
@d.pointsize = scale_fontsize(@title_font_size)
@d.font_weight = BoldWeight
@d.gravity = NorthGravity
@d = @d.annotate_scaled( @base_image,
@raw_columns, 1.0,
0, @top_margin,
@title, @scale)
end
# Draws column labels below graph, centered over x_offset
#--
# TODO Allow WestGravity as an option
def draw_label(x_offset, index)
return if @hide_line_markers
if !@labels[index].nil? && @labels_seen[index].nil?
y_offset = @graph_bottom + LABEL_MARGIN
@d.fill = @font_color
@d.font = @font if @font
@d.stroke('transparent')
@d.font_weight = NormalWeight
@d.pointsize = scale_fontsize(@marker_font_size)
@d.gravity = NorthGravity
@d = @d.annotate_scaled(@base_image,
1.0, 1.0,
x_offset, y_offset,
@labels[index], @scale)
@labels_seen[index] = 1
debug { @d.line 0.0, y_offset, @raw_columns, y_offset }
end
end
# Shows an error message because you have no data.
def draw_no_data
@d.fill = @font_color
@d.font = @font if @font
@d.stroke('transparent')
@d.font_weight = NormalWeight
@d.pointsize = scale_fontsize(80)
@d.gravity = CenterGravity
@d = @d.annotate_scaled( @base_image,
@raw_columns, @raw_rows/2.0,
0, 10,
@no_data_message, @scale)
end
# Finds the best background to render based on the provided theme options.
#
# Creates a @base_image to draw on.
def render_background
case @theme_options[:background_colors]
when Array
@base_image = render_gradiated_background(*@theme_options[:background_colors])
when String
@base_image = render_solid_background(@theme_options[:background_colors])
else
@base_image = render_image_background(*@theme_options[:background_image])
end
end
# Make a new image at the current size with a solid +color+.
def render_solid_background(color)
Image.new(@columns, @rows) {
self.background_color = color
}
end
# Use with a theme definition method to draw a gradiated background.
def render_gradiated_background(top_color, bottom_color)
Image.new(@columns, @rows,
GradientFill.new(0, 0, 100, 0, top_color, bottom_color))
end
# Use with a theme to use an image (800x600 original) background.
def render_image_background(image_path)
image = Image.read(image_path)
if @scale != 1.0
image[0].resize!(@scale) # TODO Resize with new scale (crop if necessary for wide graph)
end
image[0]
end
# Use with a theme to make a transparent background
def render_transparent_background
Image.new(@columns, @rows) do
self.background_color = 'transparent'
end
end
# Resets everything to defaults (except data).
def reset_themes
@color_index = 0
@labels_seen = {}
@theme_options = {}
@d = Draw.new
# Scale down from 800x600 used to calculate drawing.
@d = @d.scale(@scale, @scale)
end
def scale(value) # :nodoc:
value * @scale
end
# Return a comparable fontsize for the current graph.
def scale_fontsize(value)
new_fontsize = value * @scale
# return new_fontsize < 10.0 ? 10.0 : new_fontsize
return new_fontsize
end
def clip_value_if_greater_than(value, max_value) # :nodoc:
(value > max_value) ? max_value : value
end
# Overridden by subclasses such as stacked bar.
def larger_than_max?(data_point, index=0) # :nodoc:
data_point > @maximum_value
end
def less_than_min?(data_point, index=0) # :nodoc:
data_point < @minimum_value
end
# Overridden by subclasses that need it.
def max(data_point, index) # :nodoc:
data_point
end
# Overridden by subclasses that need it.
def min(data_point, index) # :nodoc:
data_point
end
def significant(inc) # :nodoc:
return 1.0 if inc == 0 # Keep from going into infinite loop
factor = 1.0
while (inc < 10)
inc *= 10
factor /= 10
end
while (inc > 100)
inc /= 10
factor *= 10
end
res = inc.floor * factor
if (res.to_i.to_f == res)
res.to_i
else
res
end
end
# Sort with largest overall summed value at front of array so it shows up
# correctly in the drawn graph.
def sort_norm_data
@norm_data.sort! { |a,b| sums(b[DATA_VALUES_INDEX]) <=> sums(a[DATA_VALUES_INDEX]) }
end
def sums(data_set) # :nodoc:
total_sum = 0
data_set.collect {|num| total_sum += num.to_f }
total_sum
end
# Used by StackedBar and child classes.
#
# May need to be moved to the StackedBar class.
def get_maximum_by_stack
# Get sum of each stack
max_hash = {}
@data.each do |data_set|
data_set[DATA_VALUES_INDEX].each_with_index do |data_point, i|
max_hash[i] = 0.0 unless max_hash[i]
max_hash[i] += data_point.to_f
end
end
# @maximum_value = 0
max_hash.keys.each do |key|
@maximum_value = max_hash[key] if max_hash[key] > @maximum_value
end
@minimum_value = 0
end
def make_stacked # :nodoc:
stacked_values = Array.new(@column_count, 0)
@data.each do |value_set|
value_set[DATA_VALUES_INDEX].each_with_index do |value, index|
stacked_values[index] += value
end
value_set[DATA_VALUES_INDEX] = stacked_values.dup
end
end
private
# Takes a block and draws it if DEBUG is true.
#
# Example:
# debug { @d.rectangle x1, y1, x2, y2 }
def debug
if DEBUG
@d = @d.fill 'transparent'
@d = @d.stroke 'turquoise'
@d = yield
end
end
# Returns the next color in your color list.
def increment_color
@color_index = (@color_index + 1) % @colors.length
return @colors[@color_index - 1]
end
# Return a formatted string representing a number value that should be
# printed as a label.
def label(value)
if (@spread.to_f % @marker_count.to_f == 0) || !@y_axis_increment.nil?
return value.to_i.to_s
end
if @spread > 10.0
sprintf("%0i", value)
elsif @spread >= 3.0
sprintf("%0.2f", value)
else
value.to_s
end
end
# Returns the height of the capital letter 'X' for the current font and
# size.
#
# Not scaled since it deals with dimensions that the regular scaling will
# handle.
def calculate_caps_height(font_size)
@d.pointsize = font_size
@d.get_type_metrics(@base_image, 'X').height
end
# Returns the width of a string at this pointsize.
#
# Not scaled since it deals with dimensions that the regular
# scaling will handle.
def calculate_width(font_size, text)
@d.pointsize = font_size
@d.get_type_metrics(@base_image, text.to_s).width
end
end # Gruff::Base
class IncorrectNumberOfDatasetsException < StandardError; end
end # Gruff
module Magick
class Draw
# Additional method to scale annotation text since Draw.scale doesn't.
def annotate_scaled(img, width, height, x, y, text, scale)
scaled_width = (width * scale) >= 1 ? (width * scale) : 1
scaled_height = (height * scale) >= 1 ? (height * scale) : 1
self.annotate( img,
scaled_width, scaled_height,
x * scale, y * scale,
text)
end
end
end # Magick