Parent

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

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.

# File lib/SVG/Graph/TimeSeries.rb, line 151
def add_data data
  data[:data].each_index do |i|
    data[:data][i] = parse_time(data[:data][i]).to_i if i % 2 == 0
  end
  super(data)
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'

# File lib/SVG/Graph/TimeSeries.rb, line 108
def set_defaults
  super
  init_with(
    #:max_time_span     => '',
    :x_label_format     => '%Y-%m-%d %H:%M:%S',
    :popup_format       => '%Y-%m-%d %H:%M:%S'
  )
end

Protected Instance Methods

format(x, y, description) click to toggle source
# File lib/SVG/Graph/TimeSeries.rb, line 171
def format x, y, description
  info = [
    Time.at(x).strftime(popup_format),
    round_popups ? (y * 100).to_i / 100 : y,
    description
  ].compact.join(', ')
end
get_x_labels() click to toggle source
# File lib/SVG/Graph/TimeSeries.rb, line 179
def get_x_labels
  get_x_values.collect { |v| Time.at(v).strftime( x_label_format ) }
end
max_x_value=(value) click to toggle source
# File lib/SVG/Graph/TimeSeries.rb, line 166
def max_x_value=(value)
  t = parse_time(value)
  @max_x_value = t.to_i
end
min_x_value=(value) click to toggle source
# File lib/SVG/Graph/TimeSeries.rb, line 161
def min_x_value=(value)
  t = parse_time(value)
  @min_x_value = t.to_i
end

[Validate]

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