### Home Classes Methods

### In Files

- lib/SVG/Graph/Line.rb

### Parent

SVG::Graph::Graph

### Methods

- ::new
- #calc_coords
- #calculate_left_margin
- #draw_data
- #get_css
- #get_x_labels
- #get_y_labels
- #max_value
- #min_value
- #set_defaults

### Class/Module Index

Quicksearch

- SVG
- SVG::Graph
- SVG::Graph::Bar
- SVG::Graph::BarBase
- SVG::Graph::BarHorizontal
- SVG::Graph::Graph
- SVG::Graph::Line
- SVG::Graph::Pie
- SVG::Graph::Plot
- SVG::Graph::Schedule
- SVG::Graph::TimeSeries
- DataPoint
- Object

No matching classes.

# SVG::Graph::Line

### Create presentation quality SVG line graphs easily

# Synopsis

    require 'SVG/Graph/Line'

    fields = %w(Jan Feb Mar);
    data_sales_02 = [12, 45, 21]
    data_sales_03 = [15, 30, 40]

    graph = SVG::Graph::Line.new({
            :height => 500,
            :width => 300,
      :fields => fields,
    })

    graph.add_data({
            :data => data_sales_02,
      :title => 'Sales 2002',
    })

    graph.add_data({
            :data => data_sales_03,
      :title => 'Sales 2003',
    })

    print "Content-type: image/svg+xml\r\n\r\n";
    print graph.burn();

# Description

This object aims to allow you to easily create high quality SVG line graphs. You can either use the default style sheet or supply your own. Either way there are many options which can be configured to give you control over how the graph is generated - with or without a key, data elements at each point, title, subtitle etc.

# Examples

www.germane-software/repositories/public/SVG/test/single.rb

# Notes

The default stylesheet handles upto 10 data sets, if you use more you must create your own stylesheet and add the additional settings for the extra data sets. You will know if you go over 10 data sets as they will have no style and be in black.

# See also

- SVG::Graph::Graph

- SVG::Graph::BarHorizontal

- SVG::Graph::Bar

- SVG::Graph::Pie

- SVG::Graph::Plot

- SVG::Graph::TimeSeries

## Author

Sean E. Russell <serATgermaneHYPHENsoftwareDOTcom>

Copyright 2004 Sean E. Russell This software is available under the Ruby license

### Attributes

area_fill[RW]

Fill in the area under the plot if true

show_data_points[RW]

Show a small circle on the graph where the line goes from one point to the next.

stacked[RW]

    Accumulates each data set. (i.e. Each point increased by sum of

all previous series at same point). Default is 0, set to '1' to show.

### Public Class Methods

new(config) click to toggle source

The constructor takes a hash reference, fields (the names for each field on the X axis) MUST be set, all other values are defaulted to those shown above - with the exception of style_sheet which defaults to using the internal style sheet.

    # File lib/SVG/Graph/Line.rb, line 85
    def initialize config
        raise "fields was not supplied or is empty" unless config[:fields] &&
        config[:fields].kind_of?(Array) &&
        config[:fields].length > 0
        super
    end

### Public Instance Methods

set_defaults() click to toggle source

In addition to the defaults set in Graph::initialize, sets

show_data_points

  true

show_data_values

  true

stacked

  false

area_fill

  false

    # File lib/SVG/Graph/Line.rb, line 97
    def set_defaults
    init_with(
    :show_data_points   => true,
    :show_data_values   => true,
    :stacked            => false,
    :area_fill          => false
    )

    self.top_align = self.top_font = self.right_align = self.right_font = 1
    end

### Protected Instance Methods

calc_coords(field, value, width = field_width, height = field_height) click to toggle source

    # File lib/SVG/Graph/Line.rb, line 175
    def calc_coords(field, value, width = field_width, height = field_height)
      coords = {:x => 0, :y => 0}
      coords[:x] = width * field
      coords[:y] = @graph_height - value * height

      return coords
    end

calculate_left_margin() click to toggle source

    # File lib/SVG/Graph/Line.rb, line 149
    def calculate_left_margin
      super
      label_left = @config[:fields][0].length / 2 * font_size * 0.6
      @border_left = label_left if label_left > @border_left
    end

draw_data() click to toggle source

    # File lib/SVG/Graph/Line.rb, line 183
    def draw_data
      minvalue = min_value
      fieldheight = (@graph_height.to_f - font_size*2*top_font) /
                       (get_y_labels.max - get_y_labels.min)
      fieldwidth = field_width
      line = @data.length

      prev_sum = Array.new(@config[:fields].length).fill(0)
      cum_sum = Array.new(@config[:fields].length).fill(-minvalue)

      for data in @data.reverse
        lpath = ""
        apath = ""

        if not stacked then cum_sum.fill(-minvalue) end

        data[:data].each_index do |i|
          cum_sum[i] += data[:data][i]

          c = calc_coords(i, cum_sum[i], fieldwidth, fieldheight)

          lpath << "#{c[:x]} #{c[:y]} "
        end

        if area_fill
          if stacked then
            (prev_sum.length - 1).downto 0 do |i|
              c = calc_coords(i, prev_sum[i], fieldwidth, fieldheight)

              apath << "#{c[:x]} #{c[:y]} "
            end

            c = calc_coords(0, prev_sum[0], fieldwidth, fieldheight)
          else
            apath = "V#@graph_height"
            c = calc_coords(0, 0, fieldwidth, fieldheight)
          end

          @graph.add_element("path", {
            "d" => "M#{c[:x]} #{c[:y]} L" + lpath + apath + "Z",
            "class" => "fill#{line}"
          })
        end

        @graph.add_element("path", {
          "d" => "M0 #@graph_height L" + lpath,
          "class" => "line#{line}"
        })

        if show_data_points || show_data_values
          cum_sum.each_index do |i|
            if show_data_points
              @graph.add_element( "circle", {
                "cx" => (fieldwidth * i).to_s,
                "cy" => (@graph_height - cum_sum[i] * fieldheight).to_s,
                "r" => "2.5",
                "class" => "dataPoint#{line}"
              })
            end
            make_datapoint_text(
              fieldwidth * i,
              @graph_height - cum_sum[i] * fieldheight - 6,
              cum_sum[i] + minvalue
            )
          end
        end

        prev_sum = cum_sum.dup
        line -= 1
      end
    end

get_css() click to toggle source

    # File lib/SVG/Graph/Line.rb, line 256
    def get_css
      return /* default line styles */.line1{        fill: none;        stroke: #ff0000;        stroke-width: 1px;     }.line2{        fill: none;        stroke: #0000ff;        stroke-width: 1px;     }.line3{        fill: none;        stroke: #00ff00;        stroke-width: 1px;     }.line4{        fill: none;        stroke: #ffcc00;        stroke-width: 1px;     }.line5{        fill: none;        stroke: #00ccff;        stroke-width: 1px;     }.line6{        fill: none;        stroke: #ff00ff;        stroke-width: 1px;     }.line7{        fill: none;        stroke: #00ffff;        stroke-width: 1px;     }.line8{        fill: none;        stroke: #ffff00;        stroke-width: 1px;     }.line9{        fill: none;        stroke: #ccc6666;        stroke-width: 1px;     }.line10{        fill: none;        stroke: #663399;        stroke-width: 1px;     }.line11{        fill: none;        stroke: #339900;        stroke-width: 1px;     }.line12{        fill: none;        stroke: #9966FF;        stroke-width: 1px;     }/* default fill styles */.fill1{        fill: #cc0000;        fill-opacity: 0.2;        stroke: none;}.fill2{        fill: #0000cc;        fill-opacity: 0.2;        stroke: none;}.fill3{        fill: #00cc00;        fill-opacity: 0.2;        stroke: none;}.fill4{        fill: #ffcc00;        fill-opacity: 0.2;        stroke: none;}.fill5{        fill: #00ccff;        fill-opacity: 0.2;        stroke: none;}.fill6{        fill: #ff00ff;        fill-opacity: 0.2;        stroke: none;}.fill7{        fill: #00ffff;        fill-opacity: 0.2;        stroke: none;}.fill8{        fill: #ffff00;        fill-opacity: 0.2;        stroke: none;}.fill9{        fill: #cc6666;        fill-opacity: 0.2;        stroke: none;}.fill10{        fill: #663399;        fill-opacity: 0.2;        stroke: none;}.fill11{        fill: #339900;        fill-opacity: 0.2;        stroke: none;}.fill12{        fill: #9966FF;        fill-opacity: 0.2;        stroke: none;}/* default line styles */.key1,.dataPoint1{        fill: #ff0000;        stroke: none;        stroke-width: 1px;     }.key2,.dataPoint2{        fill: #0000ff;        stroke: none;        stroke-width: 1px;     }.key3,.dataPoint3{        fill: #00ff00;        stroke: none;        stroke-width: 1px;     }.key4,.dataPoint4{        fill: #ffcc00;        stroke: none;        stroke-width: 1px;     }.key5,.dataPoint5{        fill: #00ccff;        stroke: none;        stroke-width: 1px;     }.key6,.dataPoint6{        fill: #ff00ff;        stroke: none;        stroke-width: 1px;     }.key7,.dataPoint7{        fill: #00ffff;        stroke: none;        stroke-width: 1px;     }.key8,.dataPoint8{        fill: #ffff00;        stroke: none;        stroke-width: 1px;     }.key9,.dataPoint9{        fill: #cc6666;        stroke: none;        stroke-width: 1px;     }.key10,.dataPoint10{        fill: #663399;        stroke: none;        stroke-width: 1px;     }.key11,.dataPoint11{        fill: #339900;        stroke: none;        stroke-width: 1px;     }.key12,.dataPoint12{        fill: #9966FF;        stroke: none;        stroke-width: 1px;     }
    end

get_x_labels() click to toggle source

    # File lib/SVG/Graph/Line.rb, line 145
    def get_x_labels
      @config[:fields]
    end

get_y_labels() click to toggle source

    # File lib/SVG/Graph/Line.rb, line 155
    def get_y_labels
      maxvalue = max_value
      minvalue = min_value
      range = maxvalue - minvalue
      top_pad = range == 0 ? 10 : range / 20.0
      scale_range = (maxvalue + top_pad) - minvalue

      scale_division = scale_divisions || (scale_range / 10.0)

      if scale_integers
        scale_division = scale_division < 1 ? 1 : scale_division.round
      end

      rv = []
      maxvalue = maxvalue%scale_division == 0 ?
        maxvalue : maxvalue + scale_division
      minvalue.step( maxvalue, scale_division ) {|v| rv << v}
      return rv
    end

max_value() click to toggle source

    # File lib/SVG/Graph/Line.rb, line 111
    def max_value
        max = 0

        if (stacked == true) then
          sums = Array.new(@config[:fields].length).fill(0)

          @data.each do |data|
            sums.each_index do |i|
              sums[i] += data[:data][i].to_f
            end
          end

          max = sums.max
        else
          max = @data.collect{|x| x[:data].max}.max
        end

        return max
    end

min_value() click to toggle source

    # File lib/SVG/Graph/Line.rb, line 131
    def min_value
      min = 0

      if (min_scale_value.nil? == false) then
        min = min_scale_value
      elsif (stacked == true) then
        min = @data[-1][:data].min
      else
        min = @data.collect{|x| x[:data].min}.min
      end

      return min
    end

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