require 'rexml/document' require 'SVG/Graph/Graph' require 'SVG/Graph/BarBase' module SVG module Graph # === Create presentation quality SVG bar graphs easily # # = Synopsis # # require 'SVG/Graph/Bar' # # fields = %w(Jan Feb Mar); # data_sales_02 = [12, 45, 21] # # graph = SVG::Graph::Bar.new( # :height => 500, # :width => 300, # :fields => fields # ) # # graph.add_data( # :data => data_sales_02, # :title => 'Sales 2002' # ) # # 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[http://www.w3c.org/tr/svg bar 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. # # = Notes # # The default stylesheet handles upto 12 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 12 data sets as they will have no style and # be in black. # # = Examples # # * http://germane-software.com/repositories/public/SVG/test/test.rb # # = See also # # * SVG::Graph::Graph # * SVG::Graph::BarHorizontal # * SVG::Graph::Line # * SVG::Graph::Pie # * SVG::Graph::Plot # * SVG::Graph::TimeSeries class Bar < BarBase include REXML # See Graph::initialize and BarBase::set_defaults def set_defaults super self.top_align = self.top_font = 1 end protected def get_x_labels @config[:fields] end 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 def x_label_offset( width ) width / 2.0 end def draw_data minvalue = min_value fieldwidth = field_width unit_size = (@graph_height.to_f - font_size*2*top_font) / (get_y_labels.max - get_y_labels.min) bargap = bar_gap ? (fieldwidth < 10 ? fieldwidth / 2 : 10) : 0 bar_width = fieldwidth - bargap bar_width /= @data.length if stack == :side x_mod = (@graph_width-bargap)/2 - (stack==:side ? bar_width/2 : 0) bottom = @graph_height field_count = 0 @config[:fields].each_index { |i| dataset_count = 0 for dataset in @data # cases (assume 0 = +ve): # value min length # +ve +ve value - min # +ve -ve value - 0 # -ve -ve value.abs - 0 value = dataset[:data][i] left = (fieldwidth * field_count) length = (value.abs - (minvalue > 0 ? minvalue : 0)) * unit_size # top is 0 if value is negative top = bottom - (((value < 0 ? 0 : value) - minvalue) * unit_size) left += bar_width * dataset_count if stack == :side @graph.add_element( "rect", { "x" => left.to_s, "y" => top.to_s, "width" => bar_width.to_s, "height" => length.to_s, "class" => "fill#{dataset_count+1}" }) make_datapoint_text(left + bar_width/2.0, top - 6, value.to_s) dataset_count += 1 end field_count += 1 } end end end end