Module: Scale

Included in:
Graph
Defined in:
lib/scale.rb

Instance Method Summary collapse

Instance Method Details

#clear_scale ⇒ Object

You’ll need to call this function only if you’re planning to draw a second chart in the rendered picture. Calling this function will clear the current scaling parameters thus you’ll need to call again the draw_scale function before drawing any new chart.



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# File 'lib/scale.rb', line 5

def clear_scale
  @vmin     = nil
  @vmax       = nil
  @v_x_min   = nil
  @v_x_max      = nil
  @divisions  = 0
  @x_divisions = 0
end

#draw_right_scale(data, data_description, scale_mode, r, g, b, draw_ticks = true, angle = 0, decimals = 1, with_margin = false, skip_labels = 1) ⇒ Object

Wrapper to the draw_scale function allowing a second scale to be drawn It takes the same parameters of the draw_scale function. The scale values will be written on the right side of the graph area.



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# File 'lib/scale.rb', line 32

def draw_right_scale(data,data_description,scale_mode,r,g,b,draw_ticks=true,angle=0,decimals=1,with_margin=false,skip_labels=1)
  self.	draw_scale(data, data_description, scale_mode, r, g, b,draw_ticks,angle,decimals,with_margin,skip_labels,true)
end

#draw_scale(data, data_description, scale_mode, r, g, b, draw_ticks = true, angle = 0, decimals = 1, with_margin = false, skip_labels = 1, right_scale = false) ⇒ Object

This function will draw both axis and write values on it. You can disable the labelling of the axis setting draw_ticks to false. angle can be used to rotate the vertical ticks labels. decimal specify the number of decimal values we want to keep. Setting draw_ticks to false will not draw vertical & horizontal ticks on the axis ( labels will also not be written ). There is four way of computing scales :

  • Getting Max & Min values per serie : scale_mode = Rchart::SCALE_NORMAL

  • Like the previous one but setting the min value to 0 : scale_mode = Rchart::SCALE_START0

  • Getting the series cumulative Max & Min values : scale_mode = Rchart::SCALE_ADDALL

  • Like the previous one but setting the min value to 0 : scale_mode = Rchart::SCALE_ADDALLSTART0

This will depends on the kind of graph you are drawing, Drawing graphs were you want to fix the min value to 0 you must use the Rchart::SCALE_START0 option. You can display only one x label every xi labels using the skip_labels parameter. Keeping with_margin to false will make the chart use all the width of the graph area. For most graphs the rendering will be better. In some circumstances you’ll have to set it to true ( introducing left & right margin ) : bar charts will require it.



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# File 'lib/scale.rb', line 46

def draw_scale(data,data_description,scale_mode,r,g,b,draw_ticks=true,angle=0,decimals=1,with_margin=false,skip_labels=1,right_scale=false)
  # Validate the Data and DataDescription array
  data = self.validate_data("draw_scale",data)
  c_text_color         = allocate_color(@picture,r,g,b)
  self.draw_line(@g_area_x1,@g_area_y1,@g_area_x1,@g_area_y2,r,g,b)
  self.draw_line(@g_area_x1,@g_area_y2,@g_area_x2,@g_area_y2,r,g,b)
  scale =0
  divisions =0
  if(@vmin.nil? && @vmax.nil?)
    if (!data_description["values"][0].nil?)
      #My hack TODO for LINE GRAPH
      if data_description["values"].is_a?(Array)
        @vmin =data[0][data_description["values"][0]]
        @vmax =data[0][data_description["values"][0]]
      else
        @vmin =data[0][data_description["values"][0]]
        @vmax =data[0][data_description["values"]]
      end

    else
      @vmin = 2147483647
      @vmax = -2147483647
    end
#       /* Compute Min and Max values */
    if(scale_mode == Rchart::SCALE_NORMAL || scale_mode == Rchart::SCALE_START0)
      @vmin = 0 if (scale_mode == Rchart::SCALE_START0 )

      data.each do |key|
        data_description["values"].each do |col_name|
          if(!key[col_name].nil?)
            value = key[col_name]
            if (value.is_a?(Numeric))
              @vmax = value if ( @vmax < value)
              @vmin = value  if ( @vmin > value)
            end
          end
        end
      end
    elsif ( scale_mode == Rchart::SCALE_ADDALL || scale_mode == Rchart::SCALE_ADDALLSTART0 ) # Experimental
      @vmin = 0 if (scale_mode == Rchart::SCALE_ADDALLSTART0)
      data.each do |key|
        sum = 0
        data_description["values"].each do|col_name|
          if (!key[col_name].nil?)
            value =key[col_name]
            sum  += value if ((value).is_a?(Numeric))
          end
        end
        @vmax = sum if (@vmax < sum)
        @vmin = sum if (@vmin > sum)
      end

    end

    if(@vmax.is_a?(String))
      @vmax = @vmax.gsub(/\.[0-9]+/,'')+1 if (@vmax > @vmax.gsub(/\.[0-9]+/,'') )
    end
    # If all values are the same */
    if ( @vmax == @vmin )
      if ( @vmax >= 0 )
        @vmax = @vmax+1
      else
        @vmin = @vmin-1
      end
    end

    data_range = @vmax - @vmin
    data_range = 0.1 if (data_range.to_f == 0.0)

    #Compute automatic scaling */
    scale_ok = false
    factor = 1
    min_div_height = 25
    max_divs = (@g_area_y2 - @g_area_y1)*1.0 / min_div_height

    if (@vmin == 0 && @vmax == 0 )
      @vmin = 0
      @vmax = 2
      scale = 1
      divisions = 2
    elsif (max_divs > 1)
      while(!scale_ok)
        scale1 = ( @vmax - @vmin )*1.0 / factor
        scale2 = ( @vmax - @vmin )*1.0 /factor / 2
    #    scale4 = ( @vmax - @vmin )*1.0 / factor / 4
        if ( scale1 > 1 && scale1 <= max_divs && !scale_ok)
          scale_ok = true
          divisions = (scale1).floor
          scale = 1
        end
        if (scale2 > 1 && scale2 <= max_divs && !scale_ok)
          scale_ok = true
          divisions = (scale2).floor
          scale = 2
        end
        if (!scale_ok)
          factor = factor * 10 if ( scale2 > 1 )
          factor = factor / 10  if ( scale2 < 1 )
        end
      end # while end
      if ((((@vmax*1.0 / scale) / factor)).floor != ((@vmax*1.0 / scale) / factor))
        grid_id     = ( @vmax*1.0 / scale / factor).floor  + 1
        @vmax       = grid_id * scale * factor
        divisions   = divisions+1
      end

      if (((@vmin*1.0 / scale) / factor).floor != ((@vmin*1.0 / scale) / factor))

        grid_id     = ( @vmin*1.0 / scale / factor).floor
        @vmin       = grid_id * scale * factor*1.0
        divisions   = divisions+1
      end

    else #/* Can occurs for small graphs */
      scale = 1
    end
    divisions = 2 if ( divisions.nil? )

    divisions = divisions-1 if (scale == 1 && divisions%2 == 1)

  else
    divisions = @divisions
  end

  @division_count = divisions
  data_range = @vmax - @vmin
  data_range = 0.1  if (data_range.to_f == 0.0 )
  @division_height = ( @g_area_y2 - @g_area_y1 )*1.0 / divisions
  @division_ratio  = ( @g_area_y2 - @g_area_y1 )*1.0 /data_range
  @g_area_x_offset  = 0
  if ( data.count > 1 )
    if ( with_margin == false)
      @division_width = ( @g_area_x2 - @g_area_x1 )*1.0 / ((data).count-1)
    else
      @division_width = ( @g_area_x2 - @g_area_x1 ) *1.0/ (data).count
      @g_area_x_offset  = @division_width*1.0 / 2
    end
  else
    @division_width = (@g_area_x2 - @g_area_x1)*1.0
    @g_area_x_offset  = @division_width*1.0 / 2
  end

  @data_count = (data).count
  return(0) if (draw_ticks == false )
  ypos = @g_area_y2
  xmin = nil
  i =1

  while(i<= divisions+1)
    if (right_scale )
      self.draw_line(@g_area_x2,ypos,@g_area_x2+5,ypos,r,g,b)
    else
      self.draw_line(@g_area_x1,ypos,@g_area_x1-5,ypos,r,g,b)
    end
    value     = @vmin*1.0 + (i-1) * (( @vmax - @vmin ) / divisions)
    value     = (round_of(value * (10**decimals),2)) / (10**decimals)
    value= value.round if value.floor == value.ceil
    value = "#{value} #{data_description['unit']['y']}"  if ( data_description["format"]["y"]== "number")
    value = self.to_time(value)                  if ( data_description["format"]["y"] == "time" )
    value = self.to_date(value)                  if ( data_description["format"]["y"] == "date" )
    value = self.to_metric(value)                if ( data_description["format"]["Y"] == "metric" )
    value = self.to_currency(value)             if ( data_description["format"]["Y"] == "currency" )
    position  = image_ftb_box(@font_size,0,@font_name,value)
    text_width =position[2]-position[0]
    if ( right_scale )
      image_ttf_text(@picture,@font_size,0,@g_area_x2+10,ypos+(@font_size/2),c_text_color,@font_name,value)
      xmin = @g_area_x2+15+text_width if (xmin.nil? || xmin < @g_area_x2+15+text_width  )
    else
      image_ttf_text(@picture,@font_size,0,@g_area_x1-10-text_width,ypos+(@font_size/2),c_text_color,@font_name,value)
      xmin = @g_area_x1-10-text_width if (  xmin.nil? || xmin > @g_area_x1-10-text_width)
    end
    ypos = ypos - @division_height
    i = i+1
  end
  # Write the Y Axis caption if set */

  if (!data_description["axis"].nil? && !data_description["axis"]["y"].nil? )
    position   = image_ftb_box(@font_size,90,@font_name,data_description["axis"]["y"])
    text_height = (position[1]).abs+(position[3]).abs
    text_top    = ((@g_area_y2 - @g_area_y1) / 2) + @g_area_y1 + (text_height/2)

    if (right_scale )
      image_ttf_text(@picture,@font_size,90,xmin+@font_size,text_top,c_text_color,@font_name,data_description["axis"]["y"])
    else
      image_ttf_text(@picture,@font_size,90,xmin-@font_size,text_top,c_text_color,@font_name,data_description["axis"]["y"])
    end
  end
  # Horizontal Axis */
  xpos = @g_area_x1 + @g_area_x_offset
  id = 1
  ymax = nil
  data.each do |key|
    if ( id % skip_labels == 0 )
      self.draw_line((xpos).floor,@g_area_y2,(xpos).floor,@g_area_y2+5,r,g,b)
      value      =key[data_description["position"]]
      value =  "#{value} #{data_description['unit']['x']}" if ( data_description["format"]["x"] == "number" )
      value = self.to_time(value)       if ( data_description["format"]["x"] == "time" )
      value = self.to_date(value)       if ( data_description["format"]["x"] == "date" )
      value = self.to_metric(value)     if ( data_description["format"]["x"] == "metric" )
      value = self.to_currency(value)   if ( data_description["format"]["x"] == "currency" )
      position   = image_ftb_box(@font_size,angle,@font_name,value.to_s)
      text_width  = (position[2]).abs+(position[0]).abs
      text_height = (position[1]).abs+(position[3]).abs
      if ( angle == 0 )
        ypos = @g_area_y2+18
        image_ttf_text(@picture,@font_size,angle,(xpos).floor-(text_width/2).floor,ypos,c_text_color,@font_name,value.to_s)
      else
        ypos = @g_area_y2+10+text_height
        if ( angle <= 90 )
          image_ttf_text(@picture,@font_size,angle,(xpos).floor-text_width+5,ypos,c_text_color,@font_name,value.to_s)
        else
          image_ttf_text(@picture,@font_size,angle,(xpos).floor+text_width+5,ypos,c_text_color,@font_name,value.to_s)
        end
      end
      ymax = ypos if (ymax.nil? ||(!ymax.nil? && ymax < ypos))
    end
    xpos = xpos + @division_width
    id = id+1
  end   #loop ended
  #Write the X Axis caption if set */

  if ((!data_description["axis"].nil? && !data_description["axis"]["x"].nil?) )
    position   = image_ftb_box(@font_size,90,@font_name,data_description["axis"]["x"])
    text_width  = (position[2]).abs+(position[0]).abs
    text_left   = ((@g_area_x2 - @g_area_x1) / 2) + @g_area_x1 + (text_width/2)
    image_ttf_text(@picture,@font_size,0,text_left,ymax+@font_size+5,c_text_color,@font_name,data_description["axis"]["x"].to_s)
  end

end

#draw_xy_scale(data, data_description, y_serie_name, x_serie_name, r, g, b, with_margin = 0, angle = 0, decimals = 1) ⇒ Object

This function is used by scatter charts. It will compute everything needed to draw the associated line and plot charts. You must specify the name of the two series that will be used as X and Y data. By default this function will compute the min & max values of both series, anyway you can override the automatic scaling by calling first the setFixedScale function.



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# File 'lib/scale.rb', line 279

def draw_xy_scale(data,data_description,y_serie_name,x_serie_name,r,g,b,with_margin=0,angle=0,decimals=1)

  self.validate_data("draw_xy_scale",data)
  c_text_color         = allocate_color(@picture,r,g,b)
  self.draw_line(@g_area_x1,@g_area_y1,@g_area_x1,@g_area_y2,r,g,b)
  self.draw_line(@g_area_x1,@g_area_y2,@g_area_x2,@g_area_y2,r,g,b)

  # Process Y scale */
  if(@vmin.nil? && @vmax.nil?)
    @vmin = data[0][y_serie_name]
    @vmax = data[0][y_serie_name]
    data.each do |key|
      if !key[y_serie_name].nil?
        value = key[y_serie_name]
        if (value.is_a?(Numeric))
          @vmax = value if ( @vmax < value)
          @vmin = value  if ( @vmin > value)
        end
      end
    end

    if(@vmax.is_a?(String))
      @vmax = @vmax.gsub(/\.[0-9]+/,'')+1 if (@vmax > @vmax.gsub(/\.[0-9]+/,'') )
    end
    data_range = @vmax - @vmin
    data_range = 0.1 if (data_range.to_f == 0.0 )

    #Compute automatic scaling
    scale_ok = false
    factor = 1
    min_div_height = 25
    max_divs = (@g_area_y2 - @g_area_y1)*1.0 / min_div_height
    if (@vmin == 0 && @vmax == 0 )
      @vmin = 0
      @vmax = 2
      scale = 1
      divisions = 2
    elsif (max_divs > 1)
      while(!scale_ok)
        scale1 = ( @vmax - @vmin )*1.0 / factor
        scale2 = ( @vmax - @vmin )*1.0 /factor / 2
        scale4 = ( @vmax - @vmin )*1.0 / factor / 4

        if ( scale1 > 1 && scale1 <= max_divs && !scale_ok)
          scale_ok = true
          divisions = (scale1).floor
          scale = 1
        end
        if ( scale2 > 1 && scale2 <= max_divs && !scale_ok)
          scale_ok = true
          divisions = (scale2).floor
          scale = 2
        end
        if (!scale_ok)
          factor = factor * 10.0  if ( scale2 > 1 )
          factor = factor / 10.0  if ( scale2 < 1 )
        end
      end
      if ((((@vmax*1.0 / scale) / factor)).floor != ((@vmax*1.0 / scale) / factor))
        grid_id     = ( @vmax*1.0 / scale / factor).floor  + 1
        @vmax       = grid_id * scale * factor
        divisions   = divisions+1
      end

      if (((@vmin*1.0 / scale) / factor).floor != ((@vmin*1.0 / scale) / factor))

        grid_id     = ( @vmin*1.0 / scale / factor).floor
        @vmin       = grid_id * scale * factor*1.0
        divisions   = divisions+1
      end

    else #/* Can occurs for small graphs */
      scale = 1
    end
    divisions = 2 if ( divisions.nil? )

    if ( is_real_int((@vmax-@vmin)/(divisions-1)))
      divisions-=1
    elsif ( is_real_int((@vmax-@vmin)/(divisions+1)))
      divisions+=1
    end
  else
    divisions = @divisions
  end
  @division_count = divisions

  data_range = @vmax - @vmin
  data_range = 0.1  if (data_range.to_f == 0.0 )
  @division_height = ( @g_area_y2 - @g_area_y1 )*1.0 / divisions
  @division_ratio  = ( @g_area_y2 - @g_area_y1 )*1.0 /data_range
  ypos = @g_area_y2
  xmin = nil
  i =1

  while(i<= divisions+1)
    self.draw_line(@g_area_x1,ypos,@g_area_x1-5,ypos,r,g,b)
    value     = @vmin*1.0 + (i-1) * (( @vmax - @vmin ) / divisions)
    value = value.round(decimals)
    value = value.round if value.floor == value.ceil
    value = "#{value} #{data_description['unit']['y']}"  if ( data_description["format"]["y"]== "number")
    value = self.to_time(value)                  if ( data_description["format"]["y"] == "time" )
    value = self.to_date(value)                  if ( data_description["format"]["y"] == "date" )
    value = self.to_metric(value)                if ( data_description["format"]["Y"] == "metric" )
    value = self.to_currency(value)             if ( data_description["format"]["Y"] == "currency" )

    position  = image_ftb_box(@font_size,0,@font_name,value)
    text_width =position[2]-position[0]
    image_ttf_text(@picture,@font_size,0,@g_area_x1-10-text_width,ypos+(@font_size/2),c_text_color,@font_name,value)
    xmin = @g_area_x1-10-text_width if (  xmin.nil? || xmin > @g_area_x1-10-text_width)
    ypos = ypos - @division_height
    i = i+1

  end

  # Process X scale */
  if(@v_x_min.nil? && @v_x_max.nil?)

    @v_x_min =data[0][x_serie_name]
    @v_x_max =data[0][x_serie_name]
    data.each do |key|

      if !key[x_serie_name].nil?
        value = key[x_serie_name]
        if (value.is_a?(Numeric))

          @v_x_max = value if ( @v_x_max < value)
          @v_x_min = value  if ( @v_x_min > value)
        end
      end
    end

    if (@v_x_max.is_a?(String))
      @v_x_max = @v_x_max.gsub(/\.[0-9]+/,'')+1 if (@v_x_max > @v_x_max.gsub(/\.[0-9]+/,'') )
    end

    data_range = @vmax - @vmin
    data_range = 0.1 if (data_range.to_f == 0.0 )

    # Compute automatic scaling
    scale_ok = false
    factor = 1
    min_div_width = 25
    max_divs = (@g_area_x2 - @g_area_x1) / min_div_width

    if ( @v_x_min == 0 && @v_x_max == 0 )
      @v_x_min = 0
      @v_x_max = 2
      scale = 1
      x_divisions = 2
    elsif (max_divs > 1)

      while(!scale_ok)
        scale1 = ( @v_x_max - @v_x_min ) / factor
        scale2 = ( @v_x_max - @v_x_min ) / factor / 2
        scale4 = ( @v_x_max - @v_x_min ) / factor / 4
        if ( scale1 > 1 && scale1 <= max_divs && !scale_ok)
          scale_ok = true
          x_divisions = (scale1).floor
          scale = 1
        end

        if ( scale2 > 1 && scale2 <= max_divs && !scale_ok)
          scale_ok = true
          x_divisions = (scale2).floor

          scale = 2
        end
        if (!scale_ok)
          factor = factor * 10 if ( scale2 > 1 )
          factor = factor / 10  if ( scale2 < 1 )
        end
      end

      if ( (@v_x_max*1.0 / scale / factor).floor != @v_x_max / scale / factor)
        grid_id     =  ( @v_x_max*1.0 / scale / factor).floor + 1
        @v_x_max = grid_id * scale * factor
        x_divisions+=1
      end

      if ( (@v_x_min*1.0 / scale / factor).floor != @v_x_min / scale / factor)
        grid_id     = ( @v_x_min / scale / factor).floor
        @v_x_min = grid_id * scale * factor
        x_divisions+=1
      end
    else #/* Can occurs for small graphs */
      scale = 1
    end
    x_divisions = 2 if ( x_divisions.nil? )

    if ( is_real_int((@v_x_max-@v_x_min)/(x_divisions-1)))
      x_divisions-=1
    elsif ( is_real_int((@v_x_max-@v_x_min)/(x_divisions+1)))
      x_divisions+=1
    end
  else

    x_divisions = @x_divisions
  end

  @x_division_count = divisions
  @data_count      = divisions + 2

  x_data_range = @v_x_max - @v_x_min
  x_data_range = 0.1   if ( x_data_range == 0 )

  @division_width   = ( @g_area_x2 - @g_area_x1 ) / x_divisions
  @x_division_ratio  = ( @g_area_x2 - @g_area_x1 ) / x_data_range
  xpos = @g_area_x1
  ymax =nil
  i=1

  while(i<= x_divisions+1)
    self.draw_line(xpos,@g_area_y2,xpos,@g_area_y2+5,r,g,b)
    value = @v_x_min + (i-1) * (( @v_x_max - @v_x_min ) / x_divisions)
    value = value.round(decimals)
    value = value.round if value.floor == value.ceil
    value = "#{value}#{data_description['unit']['y']}"  if ( data_description["format"]["y"] == "number")
    value = self.to_time(value)                  if ( data_description["format"]["y"] == "time" )
    value = self.to_date(value)                  if ( data_description["format"]["y"] == "date" )
    value = self.to_metric(value)                if ( data_description["format"]["Y"] == "metric" )
    value = self.to_currency(value)             if ( data_description["format"]["Y"] == "currency" )
    position  = image_ftb_box(@font_size,angle,@font_name,value)
    text_width =position[2].abs+position[0].abs
    text_height = position[1].abs+position[3].abs

    if ( angle == 0 )
      ypos = @g_area_y2+18
      image_ttf_text(@picture,@font_size,angle,(xpos).floor-(text_width/2).floor,ypos,c_text_color,@font_name,value)
    else

      ypos = @g_area_y2+10+text_height
      if ( angle <= 90 )
        image_ttf_text(@picture,@font_size,angle,(xpos).floor-text_width+5,ypos,c_text_color,@font_name,value)
      else
        image_ttf_text(@picture,@font_size,angle,(xpos).floor+text_width+5,ypos,c_text_color,@font_name,value)
      end

    end

    ymax = ypos if (ymax.nil? || ymax < ypos)
    i=i+1
    xpos = xpos + @division_width
  end
  #Write the Y Axis caption if set
  if ((!data_description["axis"].nil? && !data_description["axis"]["y"].nil?) )
    position   = image_ftb_box(@font_size,90,@font_name,data_description["axis"]["y"])
    text_height  = (position[1]).abs+(position[3]).abs
    text_top   = ((@g_area_y2 - @g_area_y1) / 2) + @g_area_y1 + (text_width/2)
    image_ttf_text(@picture,@font_size,90,xmin-@font_size,text_top,c_text_color,@font_name,data_description["axis"]["y"].to_s)
  end
  if ((!data_description["axis"].nil? && !data_description["axis"]["x"].nil?) )
    position   = image_ftb_box(@font_size,90,@font_name,data_description["axis"]["x"])
    text_width  = (position[2]).abs+(position[0]).abs
    text_left   = ((@g_area_x2 - @g_area_x1) / 2) + @g_area_x1 + (text_width/2)
    image_ttf_text(@picture,@font_size,0,text_left,ymax+@font_size+5,c_text_color,@font_name,data_description["axis"]["x"].to_s)
  end

end

#set_fixed_scale(v_min, v_max, divisions = 5, v_x_min = nil, v_x_max = nil, x_divisions = 5) ⇒ Object

Allow you to fix the scale, use this to bypass the automatic scaling You can use this function to skip the automatic scaling. vmin and vmax will be used to render the graph.



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# File 'lib/scale.rb', line 17

def set_fixed_scale(v_min,v_max,divisions=5,v_x_min=nil,v_x_max=nil,x_divisions=5)
  @vmin      = v_min.to_f
  @vmax      = v_max.to_f
  @divisions = divisions.to_f

  if (!v_x_min.nil?)
    @v_x_min      = v_x_min.to_f
    @v_x_max      = v_x_max.nil? ? 0.0 : v_x_max.to_f
    @x_divisions = x_divisions.to_f
  end
end