Class: SVG::Graph::Graph

Inherits:
Object
  • Object
show all
Includes:
REXML
Defined in:
lib/SVG/Graph/Graph.rb

Overview

Base object for generating SVG Graphs

Synopsis

This class is only used as a superclass of specialized charts. Do not attempt to use this class directly, unless creating a new chart type.

For examples of how to subclass this class, see the existing specific subclasses, such as SVG::Graph::Pie.

Examples

For examples of how to use this package, see either the test files, or the documentation for the specific class you want to use.

  • file:test/plot.rb

  • file:test/single.rb

  • file:test/test.rb

  • file:test/timeseries.rb

Description

This package should be used as a base for creating SVG graphs.

Acknowledgements

Leo Lapworth for creating the SVG::TT::Graph package which this Ruby port is based on.

Stephen Morgan for creating the TT template and SVG.

See

  • SVG::Graph::BarHorizontal

  • SVG::Graph::Bar

  • SVG::Graph::Line

  • SVG::Graph::Pie

  • SVG::Graph::Plot

  • SVG::Graph::TimeSeries

Author

Sean E. Russell <serATgermaneHYPHENsoftwareDOTcom>

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

Direct Known Subclasses

BarBase, Line, Schedule

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(config) ⇒ Graph

Initialize the graph object with the graph settings. You won’t instantiate this class directly; see the subclass for options.

width

500

height

300

x_axis_position

nil

y_axis_position

nil

show_x_guidelines

false

show_y_guidelines

true

show_data_values

true

min_scale_value

0

show_x_labels

true

stagger_x_labels

false

rotate_x_labels

false

step_x_labels

1

step_include_first_x_label

true

show_y_labels

true

rotate_y_labels

false

scale_integers

false

show_x_title

false

x_title

‘X Field names’

x_title_location

:middle | :end

show_y_title

false

y_title_text_direction

:bt | :tb

y_title

‘Y Scale’

y_title_location

:middle | :end

show_graph_title

false

graph_title

‘Graph Title’

show_graph_subtitle

false

graph_subtitle

‘Graph Sub Title’

key

true,

key_position

:right, # bottom or righ

font_size

12

title_font_size

16

subtitle_font_size

14

x_label_font_size

12

x_title_font_size

14

y_label_font_size

12

y_title_font_size

14

key_font_size

10

no_css

false

add_popups

false

number_format

‘%.2f’



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# File 'lib/SVG/Graph/Graph.rb', line 104

def initialize( config )
  @config = config
  @data = []
  #self.top_align = self.top_font = 0
  #self.right_align = self.right_font = 0

  init_with({
    :width                => 500,
    :height               => 300,
    :show_x_guidelines    => false,
    :show_y_guidelines    => true,
    :show_data_values     => true,

    :x_axis_position      => nil,
    :y_axis_position      => nil,

    :min_scale_value      => nil,

    :show_x_labels        => true,
    :stagger_x_labels     => false,
    :rotate_x_labels      => false,
    :step_x_labels        => 1,
    :step_include_first_x_label => true,

    :show_y_labels        => true,
    :rotate_y_labels      => false,
    :stagger_y_labels     => false,
    :scale_integers       => false,

    :show_x_title         => false,
    :x_title              => 'X Field names',
    :x_title_location     => :middle,  # or :end

    :show_y_title         => false,
    :y_title_text_direction => :bt,  # other option is :tb
    :y_title              => 'Y Scale',
    :y_title_location     => :middle,  # or :end

    :show_graph_title      => false,
    :graph_title          => 'Graph Title',
    :show_graph_subtitle  => false,
    :graph_subtitle        => 'Graph Sub Title',
    :key                  => true,
    :key_position          => :right, # bottom or right

    :font_size            =>12,
    :title_font_size      =>16,
    :subtitle_font_size   =>14,
    :x_label_font_size    =>12,
    :y_label_font_size    =>12,
    :x_title_font_size    =>14,
    :y_title_font_size    =>14,
    :key_font_size        =>10,

    :no_css               =>false,
    :add_popups           =>false,
    :number_format        => '%.2f'
  })
  set_defaults if self.respond_to? :set_defaults
  init_with config
end

Instance Attribute Details

#add_popups ⇒ Object

Add popups for the data points on some graphs, default is false.



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# File 'lib/SVG/Graph/Graph.rb', line 394

def add_popups
  @add_popups
end

#font_size ⇒ Object

Set the font size (in points) of the data point labels. Defaults to 12.



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# File 'lib/SVG/Graph/Graph.rb', line 363

def font_size
  @font_size
end

#graph_subtitle ⇒ Object

What the subtitle on the graph should be.



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# File 'lib/SVG/Graph/Graph.rb', line 354

def graph_subtitle
  @graph_subtitle
end

#graph_title ⇒ Object

What the title on the graph should be.



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# File 'lib/SVG/Graph/Graph.rb', line 349

def graph_title
  @graph_title
end

#height ⇒ Object

Set the height of the graph box, this is the total height

of the SVG box created - not the graph it self which auto
scales to fix the space.



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# File 'lib/SVG/Graph/Graph.rb', line 254

def height
  @height
end

#key ⇒ Object

Whether to show a key (legend), defaults to true, set to

false if you want to hide it.



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# File 'lib/SVG/Graph/Graph.rb', line 357

def key
  @key
end

#key_font_size ⇒ Object

Set the key font size. Defaults to 10.



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# File 'lib/SVG/Graph/Graph.rb', line 384

def key_font_size
  @key_font_size
end

#key_position ⇒ Object

Where the key should be positioned, defaults to

:right, set to :bottom if you want to move it.



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# File 'lib/SVG/Graph/Graph.rb', line 360

def key_position
  @key_position
end

#min_scale_value ⇒ Object

The point at which the Y axis starts, defaults to nil,

if set to nil it will default to the minimum data value.



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# File 'lib/SVG/Graph/Graph.rb', line 283

def min_scale_value
  @min_scale_value
end

#no_css ⇒ Object

Do not use CSS if set to true. Many SVG viewers do not support CSS, but not using CSS can result in larger SVGs as well as making it impossible to change colors after the chart is generated. Defaults to false.



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# File 'lib/SVG/Graph/Graph.rb', line 392

def no_css
  @no_css
end

#number_format ⇒ Object

Number format values and Y axis representation like 1.2345667 represent as 1.23, Any valid format accepted by sprintf can be specified. If you don’t want to change the format in any way you can use “%s”. Defaults to “%.2f”



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# File 'lib/SVG/Graph/Graph.rb', line 400

def number_format
  @number_format
end

#popup_radius ⇒ Object

Customize popup radius



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# File 'lib/SVG/Graph/Graph.rb', line 396

def popup_radius
  @popup_radius
end

#rotate_x_labels ⇒ Object

This turns the X axis labels by 90 degrees.

Default is false, to turn on set to true.



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# File 'lib/SVG/Graph/Graph.rb', line 297

def rotate_x_labels
  @rotate_x_labels
end

#rotate_y_labels ⇒ Object

This turns the Y axis labels by 90 degrees.

Default is true, to turn on set to false.



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# File 'lib/SVG/Graph/Graph.rb', line 300

def rotate_y_labels
  @rotate_y_labels
end

#scale_divisions ⇒ Object

This defines the gap between markers on the Y axis,

default is a 10th of the max_value, e.g. you will have
10 markers on the Y axis. NOTE: do not set this too
low - you are limited to 999 markers, after that the
graph won't generate.



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# File 'lib/SVG/Graph/Graph.rb', line 324

def scale_divisions
  @scale_divisions
end

#scale_integers ⇒ Object

Ensures only whole numbers are used as the scale divisions.

Default is false, to turn on set to true. This has no effect if
scale divisions are less than 1.



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# File 'lib/SVG/Graph/Graph.rb', line 318

def scale_integers
  @scale_integers
end

#show_data_values ⇒ Object

(Bool) Show the value of each element of data on the graph



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# File 'lib/SVG/Graph/Graph.rb', line 267

def show_data_values
  @show_data_values
end

#show_graph_subtitle ⇒ Object

Whether to show a subtitle on the graph, defaults

to false, set to true to show.



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# File 'lib/SVG/Graph/Graph.rb', line 352

def show_graph_subtitle
  @show_graph_subtitle
end

#show_graph_title ⇒ Object

Whether to show a title on the graph, defaults

to false, set to true to show.



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# File 'lib/SVG/Graph/Graph.rb', line 347

def show_graph_title
  @show_graph_title
end

#show_x_guidelines ⇒ Object

Show guidelines for the X axis, default is false



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# File 'lib/SVG/Graph/Graph.rb', line 386

def show_x_guidelines
  @show_x_guidelines
end

#show_x_labels ⇒ Object

Whether to show labels on the X axis or not, defaults

to true, set to false if you want to turn them off.



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# File 'lib/SVG/Graph/Graph.rb', line 286

def show_x_labels
  @show_x_labels
end

#show_x_title ⇒ Object

Whether to show the title under the X axis labels,

default is false, set to true to show.



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# File 'lib/SVG/Graph/Graph.rb', line 327

def show_x_title
  @show_x_title
end

#show_y_guidelines ⇒ Object

Show guidelines for the Y axis, default is true



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# File 'lib/SVG/Graph/Graph.rb', line 388

def show_y_guidelines
  @show_y_guidelines
end

#show_y_labels ⇒ Object

Whether to show labels on the Y axis or not, defaults

to true, set to false if you want to turn them off.



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# File 'lib/SVG/Graph/Graph.rb', line 314

def show_y_labels
  @show_y_labels
end

#show_y_title ⇒ Object

Whether to show the title under the Y axis labels,

default is false, set to true to show.



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# File 'lib/SVG/Graph/Graph.rb', line 335

def show_y_title
  @show_y_title
end

#stagger_x_labels ⇒ Object

This puts the X labels at alternative levels so if they

are long field names they will not overlap so easily.
Default is false, to turn on set to true.



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# File 'lib/SVG/Graph/Graph.rb', line 290

def stagger_x_labels
  @stagger_x_labels
end

#stagger_y_labels ⇒ Object

This puts the Y labels at alternative levels so if they

are long field names they will not overlap so easily.
Default is false, to turn on set to true.



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# File 'lib/SVG/Graph/Graph.rb', line 294

def stagger_y_labels
  @stagger_y_labels
end

#step_include_first_x_label ⇒ Object

Whether to (when taking “steps” between X axis labels) step from

the first label (i.e. always include the first label) or step from
the X axis origin (i.e. start with a gap if step_x_labels is greater
than one).



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# File 'lib/SVG/Graph/Graph.rb', line 311

def step_include_first_x_label
  @step_include_first_x_label
end

#step_x_labels ⇒ Object

How many “steps” to use between displayed X axis labels,

a step of one means display every label, a step of two results
in every other label being displayed (label <gap> label <gap> label),
a step of three results in every third label being displayed
(label <gap> <gap> label <gap> <gap> label) and so on.



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# File 'lib/SVG/Graph/Graph.rb', line 306

def step_x_labels
  @step_x_labels
end

#style_sheet ⇒ Object

Set the path to an external stylesheet, set to ” if

you want to revert back to using the defaut internal version.

To create an external stylesheet create a graph using the
default internal version and copy the stylesheet section to
an external file and edit from there.



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# File 'lib/SVG/Graph/Graph.rb', line 265

def style_sheet
  @style_sheet
end

#subtitle_font_size ⇒ Object

Set the subtitle font size. Defaults to 14.



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# File 'lib/SVG/Graph/Graph.rb', line 381

def subtitle_font_size
  @subtitle_font_size
end

#title_font_size ⇒ Object

Set the title font size. Defaults to 16.



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# File 'lib/SVG/Graph/Graph.rb', line 378

def title_font_size
  @title_font_size
end

#width ⇒ Object

Set the width of the graph box, this is the total width

of the SVG box created - not the graph it self which auto
scales to fix the space.



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# File 'lib/SVG/Graph/Graph.rb', line 258

def width
  @width
end

#x_axis_position ⇒ Object

By default (nil/undefined) the x-axis is at the bottom of the graph.

With this property a custom position for the x-axis can be defined.
Valid values are between :min_scale_value and maximum value of the
data.
Default: nil



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# File 'lib/SVG/Graph/Graph.rb', line 273

def x_axis_position
  @x_axis_position
end

#x_label_font_size ⇒ Object

Set the font size of the X axis labels. Defaults to 12.



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# File 'lib/SVG/Graph/Graph.rb', line 366

def x_label_font_size
  @x_label_font_size
end

#x_title ⇒ Object

What the title under X axis should be, e.g. ‘Months’.



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# File 'lib/SVG/Graph/Graph.rb', line 329

def x_title
  @x_title
end

#x_title_font_size ⇒ Object

Set the font size of the X axis title. Defaults to 14.



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# File 'lib/SVG/Graph/Graph.rb', line 369

def x_title_font_size
  @x_title_font_size
end

#x_title_location ⇒ Object

Where the x_title should be positioned, either in the :middle of the axis or

at the :end of the axis. Defaults to :middle



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# File 'lib/SVG/Graph/Graph.rb', line 332

def x_title_location
  @x_title_location
end

#y_axis_position ⇒ Object

By default (nil/undefined) the y-axis is the left border of the graph.

With this property a custom position for the y-axis can be defined.
Valid values are any values in the range of x-values (in case of a
Plot) or any of the :fields values (in case of Line/Bar Graphs, note
the '==' operator is used to find at which value to draw the axis).
Default: nil



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# File 'lib/SVG/Graph/Graph.rb', line 280

def y_axis_position
  @y_axis_position
end

#y_label_font_size ⇒ Object

Set the font size of the Y axis labels. Defaults to 12.



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# File 'lib/SVG/Graph/Graph.rb', line 372

def y_label_font_size
  @y_label_font_size
end

#y_title ⇒ Object

What the title under Y axis should be, e.g. ‘Sales in thousands’.



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# File 'lib/SVG/Graph/Graph.rb', line 341

def y_title
  @y_title
end

#y_title_font_size ⇒ Object

Set the font size of the Y axis title. Defaults to 14.



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# File 'lib/SVG/Graph/Graph.rb', line 375

def y_title_font_size
  @y_title_font_size
end

#y_title_location ⇒ Object

Where the y_title should be positioned, either in the :middle of the axis or

at the :end of the axis. Defaults to :middle



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# File 'lib/SVG/Graph/Graph.rb', line 344

def y_title_location
  @y_title_location
end

#y_title_text_direction ⇒ Object

Aligns writing mode for Y axis label.

Defaults to :bt (Bottom to Top).
Change to :tb (Top to Bottom) to reverse.



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# File 'lib/SVG/Graph/Graph.rb', line 339

def y_title_text_direction
  @y_title_text_direction
end

Instance Method Details

#add_data(conf) ⇒ Object

This method allows you do add data to the graph object. It can be called several times to add more data sets in.

data_sales_02 = [12, 45, 21];

graph.add_data({
  :data => data_sales_02,
  :title => 'Sales 2002'
})



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# File 'lib/SVG/Graph/Graph.rb', line 176

def add_data conf
  @data = [] unless (defined? @data and !@data.nil?)

  if conf[:data] and conf[:data].kind_of? Array
    @data << conf
  else
    raise "No data provided by #{conf.inspect}"
  end
end

#burn ⇒ Object

This method processes the template with the data and config which has been set and returns the resulting SVG.

This method will croak unless at least one data set has been added to the graph object.

print graph.burn



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# File 'lib/SVG/Graph/Graph.rb', line 204

def burn
  raise "No data available" unless @data.size > 0

  start_svg
  calculate_graph_dimensions
  @foreground = Element.new( "g" )
  draw_graph
  draw_titles
  draw_legend
  draw_data  # this method needs to be implemented by child classes
  @graph.add_element( @foreground )
  style

  data = ""
  @doc.write( data, 0 )

  if @config[:compress]
    if defined?(Zlib)
      inp, out = IO.pipe
      gz = Zlib::GzipWriter.new( out )
      gz.write data
      gz.close
      data = inp.read
    else
      data << "<!-- Ruby Zlib not available for SVGZ -->";
    end
  end

  return data
end

#burn_svg_only ⇒ String

Burns the graph but returns only the <svg> node as String without the Doctype and XML Declaration. This allows easy integration into existing xml documents.

Returns:

  • (String) —

    the SVG node which represents the Graph



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# File 'lib/SVG/Graph/Graph.rb', line 240

def burn_svg_only
  # initialize all instance variables by burning the graph
  burn
  f = REXML::Formatters::Pretty.new(0)
  f.compact = true
  out = ''
  f.write(@root, out)
  return out
end

#clear_data ⇒ Object

This method removes all data from the object so that you can reuse it to create a new graph but with the same config options.

graph.clear_data



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# File 'lib/SVG/Graph/Graph.rb', line 191

def clear_data
  @data = []
end