---
layout: post
title:  'Using Gems in picrate'
keywords: gem, library, picrate
permalink: gems/other_gems.html
---
```ruby
#####################################################################
# Using the ai4r gem in picrate.
# A simple example that demonstrates using
# a back-propagation neural network. Use the drop box menu to
# select a pre-built shape. To draw a test shape tick drawing check-box,
# release the mouse when drawing a discontinuous shape eg cross.
# Clear the sketch with clear button.
# Press evaluate and result is printed to the console....
####################################################################

require 'ai4r'
require 'json'

#....................

load_library :control_panel

attr_reader  :img, :img_pixels, :ci_input, :cr_input, :tr_input, :sq_input, :net, :points, :panel, :hide, :drawing, :source_string

def settings
  size(320, 320)
end

def setup
  sketch_title 'AI4R Sketch'
  control_panel do |c|
    c.title'control'
    c.look_feel 'Nimbus'
    c.checkbox :drawing
    c.button :clear
    c.button :evaluate
    c.menu :shape, ['CIRCLE', 'CROSS', 'CROSS_WITH_NOISE', 'SQUARE', 'SQUARE_WITH_NOISE', 'TRIANGLE', 'DEFAULT']
    @panel = c
  end
  @hide = false
  @source_string = open(data_path('data.json'), 'r'){ |file| file.read }
  triangle = JSON.parse(source_string)['TRIANGLE']
  square = JSON.parse(source_string)['SQUARE']
  cross = JSON.parse(source_string)['CROSS']
  circle = JSON.parse(source_string)['CIRCLE']
  @points = []
  srand 1
  @net = Ai4r::NeuralNetwork::Backpropagation.new([256, 3])
  @tr_input = triangle.flatten.collect { |input| input.to_f / 127.0}
  @sq_input = square.flatten.collect { |input| input.to_f / 127.0}
  @cr_input = cross.flatten.collect { |input| input.to_f / 127.0}
  @ci_input = circle.flatten.collect { |input| input.to_f / 127.0}
  train  
  background 255
end


def draw
  # only make control_panel visible once, or again when hide is false
  unless hide
    @hide = true
    panel.set_visible(hide)    
  end
  if drawing
    stroke_weight 32
    stroke 127
    points.each_cons(2) { |ps, pe| line ps.x, ps.y, pe.x, pe.y}
  else    
    no_fill
    stroke_weight(32)
    stroke(127)
    case @shape
    when 'CIRCLE'
      background(255)
      draw_circle
      @shape = 'DEFAULT'
    when 'CROSS'
      background(255)
      draw_cross      
      @shape = 'DEFAULT'
    when 'CROSS_WITH_NOISE','SQUARE_WITH_NOISE'
      background(255)
      draw_shape @shape
      @shape = 'DEFAULT'
    when 'SQUARE'
      background(255)
      draw_square
      @shape = 'DEFAULT'
    when 'TRIANGLE'
      background(255)
      draw_triangle
      @shape = 'DEFAULT'
    end
  end
end

def draw_shape shp
  shape = JSON.parse(source_string)[shp]
  background(255)
  no_stroke
  (0  ... width / 20).each do |i|
    (0  ... height / 20).each do |j|
      col = 255 - shape[i][j]
      fill(col)
      rect(i * 20, j * 20,  20,  20)
    end
  end
end

def train
  puts 'Training Network Please Wait'
  101.times do |i|
    error = net.train(tr_input, [1.0, 0, 0])
    error = net.train(sq_input, [0, 1.0, 0])
    error = net.train(cr_input, [0, 0, 1.0])
    error = net.train(ci_input, [0, 1.0, 1.0])
    puts "Error after iteration #{i}:\t#{format('%0.5f', error)}" if i%20 == 0
  end
end

def result_label(result)
  if result.reduce(0, :+).between?(1.9, 2.1)
    if result[0] < 0.01 && result[1].between?(0.99, 1.0) && result[2].between?(0.99, 1.0)
      return 'CIRCLE'
    else
      return 'UNKNOWN'
    end
  elsif result.reduce(0, :+).between?(0.95, 1.1)
    if result[0].between?(0.95, 1.0) && (result[1] + result[2]) < 0.01
      return 'TRIANGLE'
    elsif result[1].between?(0.95, 1.0) && (result[0] + result[2]) < 0.01
      return 'SQUARE'
    elsif result[2].between?(0.95, 1.0) && (result[1] + result[0]) < 0.01
      return 'CROSS'
    else
      return 'UNKNOWN'	  
    end
  end
  return 'UNKNOWN'
end

def mouse_dragged
  points << Vec2D.new(mouse_x, mouse_y)
end

def mouse_released
  points.clear
end

def draw_circle
  ellipse(width / 2, height / 2, 320 - 32, 320 - 32)
end

def draw_square
  rect(16, 16, 320 - 32, 320 - 32)
end

def draw_cross
  line(width / 2, 0, width / 2, 320)
  line(0, height / 2,  320 , height / 2)
end

def draw_triangle
  triangle(width / 2, 32, 24, height - 16,  width - 24, height - 16)
end

def clear
  background 255
end

def evaluate    
  load_pixels
  img_pixels = []
  (0...height).step(20) do |y|
    row = []
    (0...width).step(20) do |x|
      row << 255 - brightness(pixels[(y + 10) * width + x + 10])
    end
    img_pixels << row
  end  	
  puts "#{net.eval(img_pixels.flatten).inspect} => #{result_label(net.eval(img_pixels.flatten))}"   	
end
```
data.json
```json

{"TRIANGLE":[[0,0,0,0,0,0,0,127,127,0,0,0,0,0,0,0],[0,0,0,0,0,0,25,229,229,25,0,0,0,0,0,0],[0,0,0,0,0,0,127,127,127,127,0,0,0,0,0,0],[0,0,0,0,0,25,229,25,25,229,25,0,0,0,0,0],[0,0,0,0,0,127,127,0,0,127,127,0,0,0,0,0],[0,0,0,0,25,229,25,0,0,25,229,25,0,0,0,0],[0,0,0,0,127,127,0,0,0,0,127,127,0,0,0,0],[0,0,0,25,229,25,0,0,0,0,25,229,25,0,0,0],[0,0,0,127,127,0,0,0,0,0,0,127,127,0,0,0],[0,0,25,229,25,0,0,0,0,0,0,25,229,25,0,0],[0,0,127,127,0,0,0,0,0,0,0,0,127,127,0,0],[0,25,229,25,0,0,0,0,0,0,0,0,25,229,25,0],[0,127,127,0,0,0,0,0,0,0,0,0,0,127,127,0],[25,229,25,0,0,0,0,0,0,0,0,0,0,25,229,25],[127,127,0,0,0,0,0,0,0,0,0,0,0,0,127,127],[255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255]]
,"SQUARE":[[255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255],[255,0,0,0,0,0,0,0,0,0,0,0,0,0,0,255],[255,0,0,0,0,0,0,0,0,0,0,0,0,0,0,255],[255,0,0,0,0,0,0,0,0,0,0,0,0,0,0,255],[255,0,0,0,0,0,0,0,0,0,0,0,0,0,0,255],[255,0,0,0,0,0,0,0,0,0,0,0,0,0,0,255],[255,0,0,0,0,0,0,0,0,0,0,0,0,0,0,255],[255,0,0,0,0,0,0,0,0,0,0,0,0,0,0,255],[255,0,0,0,0,0,0,0,0,0,0,0,0,0,0,255],[255,0,0,0,0,0,0,0,0,0,0,0,0,0,0,255],[255,0,0,0,0,0,0,0,0,0,0,0,0,0,0,255],[255,0,0,0,0,0,0,0,0,0,0,0,0,0,0,255],[255,0,0,0,0,0,0,0,0,0,0,0,0,0,0,255],[255,0,0,0,0,0,0,0,0,0,0,0,0,0,0,255],[255,0,0,0,0,0,0,0,0,0,0,0,0,0,0,255],[255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255]]
,"CROSS":[[0,0,0,0,0,0,0,127,127,0,0,0,0,0,0,0],[0,0,0,0,0,0,0,127,127,0,0,0,0,0,0,0],[0,0,0,0,0,0,0,127,127,0,0,0,0,0,0,0],[0,0,0,0,0,0,0,127,127,0,0,0,0,0,0,0],[0,0,0,0,0,0,0,127,127,0,0,0,0,0,0,0],[0,0,0,0,0,0,0,127,127,0,0,0,0,0,0,0],[0,0,0,0,0,0,0,127,127,0,0,0,0,0,0,0],[127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127],[127,127,127,127,127,127,127,127,127,127,127,127,127,127,127,127],[0,0,0,0,0,0,0,127,127,0,0,0,0,0,0,0],[0,0,0,0,0,0,0,127,127,0,0,0,0,0,0,0],[0,0,0,0,0,0,0,127,127,0,0,0,0,0,0,0],[0,0,0,0,0,0,0,127,127,0,0,0,0,0,0,0],[0,0,0,0,0,0,0,127,127,0,0,0,0,0,0,0],[0,0,0,0,0,0,0,127,127,0,0,0,0,0,0,0],[0,0,0,0,0,0,0,127,127,0,0,0,0,0,0,0]]
,"CIRCLE":[[0,0,0,0,32,64,64,80,80,64,64,32,0,0,0,0],[0,0,32,64,96,103,64,64,64,64,96,96,64,32,0,0],[0,32,96,128,96,32,0,0,0,0,32,89,128,96,32,0],[0,64,128,96,18,0,0,0,0,0,0,0,64,128,64,0],[32,96,96,18,0,0,0,0,0,0,0,0,0,82,101,32],[64,103,32,0,0,0,0,0,0,0,0,0,0,32,96,64],[64,64,0,0,0,0,0,0,0,0,0,0,0,0,64,68],[80,64,0,0,0,0,0,0,0,0,0,0,0,0,64,104],[80,64,0,0,0,0,0,0,0,0,0,0,0,0,64,106],[64,64,0,0,0,0,0,0,0,0,0,0,0,0,64,70],[64,96,32,0,0,0,0,0,0,0,0,0,0,32,96,64],[32,96,88,0,0,0,0,0,0,0,0,0,0,64,119,32],[0,64,128,64,0,0,0,0,0,0,0,0,32,113,70,0],[0,32,96,128,81,32,0,0,0,0,32,64,113,96,32,0],[0,0,32,64,102,96,64,64,64,64,96,119,70,32,0,0],[0,0,0,0,32,64,69,105,106,70,64,32,0,0,0,0]]
,"TRIANGLE_WITH_NOISE":[[25,0,0,0,0,0,0,25,127,0,0,25,0,0,0,0],[0,0,0,0,76,0,25,229,229,25,0,0,0,0,76,0],[0,76,0,0,0,0,127,25,127,76,0,0,0,0,0,178],[0,0,0,178,0,25,229,25,25,229,25,0,0,0,76,0],[0,0,0,0,0,76,127,0,76,127,127,0,0,0,0,0],[0,25,0,0,25,229,25,0,25,25,229,25,0,0,0,0],[25,0,0,0,127,127,0,0,0,0,127,127,178,0,0,76],[0,0,76,76,229,25,0,0,25,0,25,229,25,0,0,0],[0,0,0,127,127,0,76,178,0,0,0,127,127,0,0,0],[0,0,25,229,25,0,0,0,0,0,0,25,229,25,0,0],[0,0,127,127,0,0,0,0,76,0,0,0,127,127,0,0],[0,25,229,25,0,0,0,0,0,0,0,0,25,229,25,0],[0,127,127,0,76,0,0,76,0,0,0,0,0,127,127,0],[25,229,25,0,0,76,0,0,0,25,0,0,0,25,229,25],[127,127,0,0,0,0,0,0,0,0,0,0,0,0,127,127],[255,255,255,255,25,255,255,255,255,255,25,255,255,255,255,255]]
,"SQUARE_WITH_NOISE":[[255,76,255,255,255,153,255,255,255,255,255,102,255,255,255,255],[255,0,0,0,0,178,0,0,0,0,0,0,0,0,0,255],[255,0,76,0,0,0,0,178,0,153,25,0,0,0,0,0],[255,0,0,0,0,0,0,0,0,0,0,0,0,0,0,255],[255,0,102,0,102,0,0,0,25,0,76,0,0,102,0,255],[255,0,0,0,0,0,0,25,0,0,0,0,0,0,0,0],[255,0,0,0,76,153,0,0,25,0,0,0,0,0,0,255],[255,0,0,0,0,0,0,102,0,0,0,0,178,0,0,255],[255,102,102,0,0,0,0,0,0,0,0,0,0,0,0,255],[255,0,178,0,0,76,0,0,0,0,0,0,0,0,0,255],[255,0,0,0,0,0,0,0,76,0,0,0,0,0,178,255],[255,0,76,0,102,0,0,0,0,153,0,0,0,0,0,255],[255,0,0,0,0,0,0,0,0,0,0,0,25,0,0,255],[255,0,0,153,0,0,0,178,0,0,0,178,0,0,0,255],[255,0,0,0,0,0,0,0,0,0,0,0,0,0,0,255],[255,255,255,255,76,255,255,255,255,0,255,255,25,255,25,255]]
,"CROSS_WITH_NOISE":[[0,0,0,0,0,0,76,76,127,0,76,0,0,0,25,0],[0,25,0,0,0,25,0,127,127,0,0,0,0,0,0,0],[0,0,0,0,0,0,0,127,127,0,0,0,76,0,0,0],[0,0,25,204,0,0,0,127,127,0,102,0,0,0,25,0],[0,0,0,0,0,76,0,127,0,0,0,0,25,0,0,0],[0,0,0,204,0,0,0,127,127,0,0,0,0,0,0,25],[0,0,0,0,0,0,0,127,127,0,76,0,0,0,0,0],[127,127,127,204,127,76,127,127,127,127,127,127,127,127,0,5],[127,127,127,127,127,127,127,127,25,127,127,127,127,25,0,0],[0,0,0,204,0,0,0,102,127,0,0,0,0,0,0,0],[0,0,0,0,0,0,0,127,127,102,0,0,0,0,0,0],[0,0,0,0,0,102,0,127,127,0,0,0,0,0,0,0],[102,0,0,102,0,0,0,127,127,0,0,0,25,0,0,0],[0,0,0,0,0,25,0,127,102,102,76,0,0,0,0,0],[0,0,0,0,0,0,0,127,127,0,0,0,255,0,0,0],[0,0,0,0,0,0,0,127,127,0,0,0,0,0,0,0]]
,"CIRCLE_WITH_NOISE":[[0,0,0,0,21,0,21,128,128,21,0,21,0,0,0,0],[0,0,8,17,128,128,110,0,0,21,128,128,98,21,0,0],[0,8,21,128,21,21,0,0,0,0,21,21,128,21,21,0],[0,0,128,21,0,0,0,0,0,0,0,0,21,128,2,0],[21,128,21,0,0,0,0,0,0,0,0,0,0,21,128,21],[0,128,42,0,0,0,0,0,0,0,0,0,0,31,128,0],[0,25,0,0,0,0,0,0,0,0,0,0,0,0,21,21],[128,0,0,0,0,0,0,0,0,0,0,0,0,0,89,128],[23,0,0,0,0,0,0,0,0,0,0,0,0,0,0,128],[21,24,12,0,0,0,0,0,0,0,0,0,0,0,128,21],[0,128,21,0,0,0,0,0,0,0,0,0,0,32,128,0],[21,42,21,21,0,0,0,0,0,0,0,0,0,21,128,27],[0,13,128,21,21,0,0,0,0,0,0,0,21,128,86,0],[0,3,21,128,21,31,0,0,0,0,21,21,128,21,0,0],[0,0,0,88,128,128,128,3,89,128,128,128,21,0,0,0],[0,0,0,0,21,0,21,128,128,21,0,21,0,0,0,0]]}
#......
```