class SVG::Graph::Schedule

For creating SVG plots of scalar temporal data

Synopsis

require 'SVG/Graph/Schedule'

# Data sets are label, start, end tripples.
data1 = [
  "Housesitting", "6/17/04", "6/19/04", 
  "Summer Session", "6/15/04", "8/15/04",
]

graph = SVG::Graph::Schedule.new( {
  :width => 640,
  :height => 480,
  :graph_title => title,
  :show_graph_title => true,
  :no_css => true,
  :scale_x_integers => true,
  :scale_y_integers => true,
  :min_x_value => 0,
  :min_y_value => 0,
  :show_data_labels => true,
  :show_x_guidelines => true,
  :show_x_title => true,
  :x_title => "Time",
  :stagger_x_labels => true,
  :stagger_y_labels => true,
  :x_label_format => "%m/%d/%y",
})

graph.add_data({
        :data => data1,
  :title => 'Data',
})

print graph.burn()

Description

Produces a graph of temporal scalar data.

Examples

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

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

bar_gap[RW]
min_x_value[RW]
popup_format[RW]

The formatting used for the popups. See x_label_format

scale_x_divisions[RW]
scale_x_integers[RW]
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.

# A data set with 1 point: Lunch from 12:30 to 14:00
d1 = [ "Lunch", "12:30", "14:00" ] 
# A data set with 2 points: "Cats" runs from 5/11/03 to 7/15/04, and
#                           "Henry V" runs from 6/12/03 to 8/20/03
d2 = [ "Cats", "5/11/03", "7/15/04",
       "Henry V", "6/12/03", "8/20/03" ]

graph.add_data( 
  :data => d1,
  :title => 'Meetings'
  :template => '%H:%M'
)
graph.add_data(
  :data => d2,
  :title => 'Plays'
  :template => '%d/%m/%y'
)

Note that the data must be in time,value pairs, and that the date format may be any date that is parseable by DateTime#parse, DateTime#strptime. The :template argument is optional. By default DateTime#parse will be used. Checkout the ruby doc for valid template notation: ruby-doc.org/stdlib-2.3.1/libdoc/date/rdoc/Date.html#method-i-strftime ruby-doc.org/stdlib-2.3.1/libdoc/date/rdoc/DateTime.html#method-c-parse ruby-doc.org/stdlib-2.3.1/libdoc/date/rdoc/DateTime.html#method-c-strptime.

Also note that, in this example, we're mixing scales; the data from d1 will probably not be discernable if both data sets are plotted on the same graph, since d1 is too granular.

# File lib/SVG/Graph/Schedule.rb, line 152
def add_data data
  @data = [] unless @data
 
  raise "No data provided by #{conf.inspect}" unless data[:data] and
                                              data[:data].kind_of? Array
  raise "Data supplied must be title,from,to tripples!  "+
    "The data provided contained an odd set of "+
    "data points" unless data[:data].length % 3 == 0
  return if data[:data].length == 0

  y = []
  x_start = []
  x_end = []
  data[:data].each_index {|i|
    im3 = i%3
    if im3 == 0
      y << data[:data][i]
    else
      if data.has_key?(:template) && data[:template].kind_of?(String)
        arr = DateTime.strptime(data[:data][i], data[:template])
      else
        arr = DateTime.parse(data[:data][i])
      end
      t = arr.to_time
      (im3 == 1 ? x_start : x_end) << t.to_i
    end
  }
  sort( x_start, x_end, y )
  @data = [x_start, x_end, y ]
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/Schedule.rb, line 89
def set_defaults
  init_with(
    :x_label_format     => '%Y-%m-%d %H:%M:%S',
    :popup_format       => '%Y-%m-%d %H:%M:%S',
    :scale_x_divisions  => false,
    :scale_x_integers   => false,
    :bar_gap            => true
  )
end

Protected Instance Methods

draw_data() click to toggle source
# File lib/SVG/Graph/Schedule.rb, line 209
def draw_data
  fieldheight = field_height
  fieldwidth = field_width

  bargap = bar_gap ? (fieldheight < 10 ? fieldheight / 2 : 10) : 0
  subbar_height = fieldheight - bargap
  
  field_count = 1
  y_mod = (subbar_height / 2) + (font_size / 2)
  min,max,div = x_range
  scale = (@graph_width.to_f - font_size*2) / (max-min)
  @data[0].each_index { |i|
    x_start = @data[0][i]
    x_end = @data[1][i]
    y = @graph_height - (fieldheight * field_count)
    bar_width = (x_end-x_start) * scale
    bar_start = x_start * scale - (min * scale)
  
    @graph.add_element( "rect", {
      "x" => bar_start.to_s,
      "y" => y.to_s,
      "width" => bar_width.to_s,
      "height" => subbar_height.to_s,
      "class" => "fill#{field_count+1}"
    })
    field_count += 1
  }
end
format(x, y) click to toggle source
# File lib/SVG/Graph/Schedule.rb, line 193
def format x, y
  Time.at( x ).strftime( popup_format )
end
get_css() click to toggle source
# File lib/SVG/Graph/Schedule.rb, line 238
      def get_css
        return <<EOL
/* default fill styles for multiple datasets (probably only use a single dataset on this graph though) */
.key1,.fill1{
        fill: #ff0000;
        fill-opacity: 0.5;
        stroke: none;
        stroke-width: 0.5px;   
}
.key2,.fill2{
        fill: #0000ff;
        fill-opacity: 0.5;
        stroke: none;
        stroke-width: 1px;     
}
.key3,.fill3{
        fill: #00ff00;
        fill-opacity: 0.5;
        stroke: none;
        stroke-width: 1px;     
}
.key4,.fill4{
        fill: #ffcc00;
        fill-opacity: 0.5;
        stroke: none;
        stroke-width: 1px;     
}
.key5,.fill5{
        fill: #00ccff;
        fill-opacity: 0.5;
        stroke: none;
        stroke-width: 1px;     
}
.key6,.fill6{
        fill: #ff00ff;
        fill-opacity: 0.5;
        stroke: none;
        stroke-width: 1px;     
}
.key7,.fill7{
        fill: #00ffff;
        fill-opacity: 0.5;
        stroke: none;
        stroke-width: 1px;     
}
.key8,.fill8{
        fill: #ffff00;
        fill-opacity: 0.5;
        stroke: none;
        stroke-width: 1px;     
}
.key9,.fill9{
        fill: #cc6666;
        fill-opacity: 0.5;
        stroke: none;
        stroke-width: 1px;     
}
.key10,.fill10{
        fill: #663399;
        fill-opacity: 0.5;
        stroke: none;
        stroke-width: 1px;     
}
.key11,.fill11{
        fill: #339900;
        fill-opacity: 0.5;
        stroke: none;
        stroke-width: 1px;     
}
.key12,.fill12{
        fill: #9966FF;
        fill-opacity: 0.5;
        stroke: none;
        stroke-width: 1px;     
}
EOL
      end
get_x_labels() click to toggle source
# File lib/SVG/Graph/Schedule.rb, line 197
def get_x_labels
  rv = get_x_values.collect { |v| Time.at(v).strftime( x_label_format ) }
end
get_y_labels() click to toggle source
# File lib/SVG/Graph/Schedule.rb, line 205
def get_y_labels
  @data[2]
end
min_x_value=(value) click to toggle source
# File lib/SVG/Graph/Schedule.rb, line 186
def min_x_value=(value)
  arr = Time.parse(value)
  t = arr.to_time
  @min_x_value = t.to_i
end
y_label_offset( height ) click to toggle source
# File lib/SVG/Graph/Schedule.rb, line 201
def y_label_offset( height )
  height / -2.0
end

Private Instance Methods

get_x_values() click to toggle source
# File lib/SVG/Graph/Schedule.rb, line 335
def get_x_values
  rv = []
  min, max, scale_division = x_range
  if timescale_divisions
    timescale_divisions =~ /(\d+) ?(days|weeks|months|years|hours|minutes|seconds)?/
    division_units = $2 ? $2 : "days"
    amount = $1.to_i
    if amount
      step =  nil
      case division_units
      when "months"
        cur = min
        while cur < max
          rv << cur
          arr = Time.at( cur ).to_a
          arr[4] += amount
          if arr[4] > 12
            arr[5] += (arr[4] / 12).to_i
            arr[4] = (arr[4] % 12)
          end
          cur = Time.local(*arr).to_i
        end
      when "years"
        cur = min
        while cur < max
          rv << cur
          arr = Time.at( cur ).to_a
          arr[5] += amount
          cur = Time.local(*arr).to_i
        end
      when "weeks"
        step = 7 * 24 * 60 * 60 * amount
      when "days"
        step = 24 * 60 * 60 * amount
      when "hours"
        step = 60 * 60 * amount
      when "minutes"
        step = 60 * amount
      when "seconds"
        step = amount
      end
      min.step( max, step ) {|v| rv << v} if step

      return rv
    end
  end
  min.step( max, scale_division ) {|v| rv << v}
  return rv
end
x_range() click to toggle source
# File lib/SVG/Graph/Schedule.rb, line 317
def x_range
  max_value = [ @data[0][-1], @data[1].max ].max 
  min_value = [ @data[0][0], @data[1].min ].min
  min_value = min_value<min_x_value ? min_value : min_x_value if min_x_value

  range = max_value - min_value
  right_pad = range == 0 ? 10 : range / 20.0
  scale_range = (max_value + right_pad) - min_value

  scale_division = scale_x_divisions || (scale_range / 10.0)

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

  [min_value, max_value, scale_division]
end