class 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¶ ↑
Only number of fileds datapoints will be drawn, additional data values are ignored. Nil values in data are skipped and interpolated as straight line to the next datapoint.
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¶ ↑
Author¶ ↑
Sean E. Russell <serATgermaneHYPHENsoftwareDOTcom>
Copyright 2004 Sean E. Russell This software is available under the Ruby license
Attributes
Fill in the area under the plot if true
Show a small circle on the graph where the line goes from one point to the next.
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
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.
SVG::Graph::Graph::new
# File lib/SVG/Graph/Line.rb, line 88 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
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 100 def set_defaults init_with( :show_data_points => true, :show_data_values => true, :stacked => false, :area_fill => false ) end
Protected Instance Methods
# File lib/SVG/Graph/Line.rb, line 183 def calc_coords(field, value, width = field_width, height = field_height) coords = {:x => 0, :y => 0} coords[:x] = width * field # make sure we do float division, otherwise coords get messed up coords[:y] = @graph_height - (value + @y_offset)/@y_scale_division.to_f * height return coords end
SVG::Graph::Graph#calculate_left_margin
# File lib/SVG/Graph/Line.rb, line 150 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
# File lib/SVG/Graph/Line.rb, line 191 def draw_data minvalue = min_value fieldheight = field_height fieldwidth = field_width line = @data.length # always zero for filling areas prev_sum = Array.new(@config[:fields].length).fill(-@y_offset) # cumulated sum (used for stacked graphs) cum_sum = Array.new(@config[:fields].length).fill(nil) for data in @data.reverse lpath = "" apath = "" # reset cum_sum if we are not in a stacked graph if not stacked then cum_sum.fill(nil) end # only consider as many datapoints as we have fields @config[:fields].each_index do |i| next if data[:data][i].nil? if cum_sum[i].nil? #first time init cum_sum[i] = data[:data][i] - minvalue else # in case of stacked cum_sum[i] += data[:data][i] end 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| next if prev_sum[i].nil? 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, -@y_offset, 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 || add_popups cum_sum.each_index do |i| # skip datapoint if nil next if cum_sum[i].nil? c = calc_coords(i, cum_sum[i], fieldwidth, fieldheight) if show_data_points shape_selection_string = data[:description][i].to_s if !data[:shape][i].nil? shape_selection_string = data[:shape][i].to_s end DataPoint.new(c[:x], c[:y], line).shape(shape_selection_string).each{|s| @graph.add_element( *s ) } end make_datapoint_text( c[:x], c[:y] - font_size/2, cum_sum[i] + minvalue) # number format shall not apply to popup (use .to_s conversion) descr = "" if !data[:description][i].to_s.empty? descr = ", #{data[:description][i].to_s}" end add_popup(c[:x], c[:y], (cum_sum[i] + minvalue).to_s + descr, "", data[:url][i].to_s) end end prev_sum = cum_sum.dup line -= 1 end end
# File lib/SVG/Graph/Line.rb, line 277 def get_css return <<EOL /* 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; } EOL end
# File lib/SVG/Graph/Line.rb, line 146 def get_x_labels @config[:fields] end
# File lib/SVG/Graph/Line.rb, line 156 def get_y_labels maxvalue = max_value minvalue = min_value range = maxvalue - minvalue # add some padding on top of the graph if range == 0 maxvalue += 10 else maxvalue += range / 20.0 end scale_range = maxvalue - minvalue @y_scale_division = scale_divisions || (scale_range / 10.0) @y_offset = 0 if scale_integers @y_scale_division = @y_scale_division < 1 ? 1 : @y_scale_division.round @y_offset = (minvalue.to_f - minvalue.floor).to_f minvalue = minvalue.floor end rv = [] minvalue.step( maxvalue, @y_scale_division ) {|v| rv << v} return rv end
# File lib/SVG/Graph/Line.rb, line 111 def max_value max = 0 if stacked 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 # compact removes nil values when computing the max max = @data.collect{ |x| x[:data].compact.max }.max end return max end
# File lib/SVG/Graph/Line.rb, line 132 def min_value min = 0 # compact removes nil values if (!min_scale_value.nil?) then min = min_scale_value elsif (stacked == true) then min = @data[-1][:data].compact.min else min = @data.collect{|x| x[:data].compact.min}.min end return min end