class SVG::Graph::TimeSeries

For creating SVG plots of scalar temporal data

Synopsis

require 'SVG/Graph/TimeSeries'

# Data sets are x,y pairs
projection = ["6/17/72", 11,    "1/11/72", 7,    "4/13/04 17:31", 11,
             "9/11/01", 9,    "9/1/85", 2,    "9/1/88", 1,    "1/15/95", 13]
actual = ["8/1/73", 18,    "3/1/77", 15,    "10/1/98", 4,
          "5/1/02", 14,    "3/1/95", 6,    "8/1/91", 12,    "12/1/87", 6,
          "5/1/84", 17,    "10/1/80", 12]

title = "Ice Cream Cone Consumption"

graph = SVG::Graph::TimeSeries.new( {
  :width => 640,
  :height => 480,
  :graph_title => title,
  :show_graph_title => true,
  :no_css => true,
  :key => true,
  :scale_x_integers => true,
  :scale_y_integers => true,
  :min_x_value => 0,
  :min_y_value => 0,
  :show_data_values => true,
  :show_x_guidelines => true,
  :show_x_title => true,
  :x_title => "Time",
  :show_y_title => true,
  :y_title => "Ice Cream Cones",
  :y_title_text_direction => :bt,
  :stagger_x_labels => true,
  :x_label_format => "%m/%d/%y",
})

graph.add_data({
        :data => projection,
  :title => 'Projected',
})

graph.add_data({
        :data => actual,
  :title => 'Actual',
})

print graph.burn()

Description

Produces a graph of temporal scalar data.

Examples

www.germane-software/repositories/public/SVG/test/timeseries.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.

Unlike the other types of charts, data sets must contain x,y pairs:

[ "12:30", 2 ]          # A data set with 1 point: ("12:30",2)
[ "01:00",2, "14:20",6] # A data set with 2 points: ("01:00",2) and
                        #                           ("14:20",6)

Note that multiple data sets within the same chart can differ in length, and that the data in the datasets needn't be in order; they will be ordered by the plot along the X-axis.

The dates must be parseable by ParseDate, but otherwise can be any order of magnitude (seconds within the hour, or years)

See also

Author

Sean E. Russell <serATgermaneHYPHENsoftwareDOTcom>

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

Attributes

popup_format[RW]

The formatting used for the popups. See x_label_format

timescale_divisions[RW]

Use this to set the spacing between dates on the axis. The value must be of the form “d+ ?(days|weeks|months|years|hours|minutes|seconds)?”

EG:

graph.timescale_divisions = "2 weeks"

will cause the chart to try to divide the X axis up into segments of two week periods.

x_label_format[RW]

The format string use do format the X axis labels. See Time::strformat

Public Instance Methods

add_data(data) click to toggle source

Add data to the plot.

d1 = [ "12:30", 2 ]          # A data set with 1 point: ("12:30",2)
d2 = [ "01:00",2, "14:20",6] # A data set with 2 points: ("01:00",2) and
                             #                           ("14:20",6)
graph.add_data( 
  :data => d1,
  :title => 'One'
)
graph.add_data(
  :data => d2,
  :title => 'Two'
)

Note that the data must be in time,value pairs. The time may be any date in a format that is parseable by ParseDate, a Time object, or a number of seconds after the unix epoch.

Calls superclass method SVG::Graph::Plot#add_data
    # File lib/SVG/Graph/TimeSeries.rb
147 def add_data data
148   data[:data].each_index do |i|
149     data[:data][i] = parse_time(data[:data][i]).to_i if i % 2 == 0
150   end
151   super(data)
152 end
set_defaults() click to toggle source

In addition to the defaults set by Graph::initialize and Plot::set_defaults, sets:

x_label_format

'%Y-%m-%d %H:%M:%S'

popup_format

'%Y-%m-%d %H:%M:%S'

Calls superclass method SVG::Graph::Plot#set_defaults
    # File lib/SVG/Graph/TimeSeries.rb
104 def set_defaults
105   super
106   init_with(
107     #:max_time_span     => '',
108     :x_label_format     => '%Y-%m-%d %H:%M:%S',
109     :popup_format       => '%Y-%m-%d %H:%M:%S'
110   )
111 end

Protected Instance Methods

format(x, y, description) click to toggle source
    # File lib/SVG/Graph/TimeSeries.rb
167 def format x, y, description
168   info = [
169     Time.at(x).strftime(popup_format),
170     round_popups ? (y * 100).to_i / 100 : y,
171     description
172   ].compact.join(', ')
173 end
get_x_labels() click to toggle source
    # File lib/SVG/Graph/TimeSeries.rb
175 def get_x_labels
176   get_x_values.collect { |v| Time.at(v).strftime( x_label_format ) }
177 end
max_x_value=(value) click to toggle source
    # File lib/SVG/Graph/TimeSeries.rb
162 def max_x_value=(value)
163   t = parse_time(value)
164   @max_x_value = t.to_i
165 end
min_x_value=(value) click to toggle source
    # File lib/SVG/Graph/TimeSeries.rb
157 def min_x_value=(value)
158   t = parse_time(value)
159   @min_x_value = t.to_i
160 end