Class Gruff::Line
In: lib/gruff/line.rb
Parent: Gruff::Base

Here‘s how to make a Line graph: 

  g = Gruff::Line.new
  g.title = "A Line Graph"
  g.data 'Fries', [20, 23, 19, 8]
  g.data 'Hamburgers', [50, 19, 99, 29]
  g.write("test/output/line.png")

There are also other options described below, such as baseline_value, baseline_color, hide_dots, and hide_lines.

Methods

baseline_color   baseline_color=   baseline_value   baseline_value=   contains_one_point_only?   dataxy   draw   draw_horizontal_reference_line   draw_reference_line   draw_vertical_reference_line   get_x_coord   new   normalize   setup_data   sort_norm_data  

Attributes

dot_radius  [RW] 
hide_dots  [RW]  Hide parts of the graph to fit more datapoints, or for a different appearance.
hide_lines  [RW]  Hide parts of the graph to fit more datapoints, or for a different appearance.
line_width  [RW]  Dimensions of lines and dots; calculated based on dataset size if left unspecified
maximum_x_value  [RW] 
minimum_x_value  [RW]  accessors for support of xy data
reference_line_default_color  [RW] 
reference_line_default_width  [RW] 
reference_lines  [RW]  Allow for reference lines ( which are like baseline … just allowing for more & on both axes )
show_vertical_markers  [RW]  Allow for vertical marker lines

Public Class methods

new(*args)

Call with target pixel width of graph (800, 400, 300), and/or ‘false’ to omit lines (points only). 

 g = Gruff::Line.new(400) # 400px wide with lines

 g = Gruff::Line.new(400, false) # 400px wide, no lines (for backwards compatibility)

 g = Gruff::Line.new(false) # Defaults to 800px wide, no lines (for backwards compatibility)

The preferred way is to call hide_dots or hide_lines instead.

Public Instance methods

baseline_value()

Get the value if somebody has defined it.

baseline_value=(new_value)

Set a value for a baseline reference line..

dataxy(name, x_data_points=[], y_data_points=[], color=nil)

This method allows one to plot a dataset with both X and Y data.

Parameters are as follows: 

  name: string, the title of the dataset
  x_data_points: an array containing the x data points for the graph
  y_data_points: an array containing the y data points for the graph
  color: hex number indicating the line color as an RGB triplet

  or

  name: string, the title of the dataset
  xy_data_points: an array containing both x and y data points for the graph
  color: hex number indicating the line color as an RGB triplet

 Notes:
  -if (x_data_points.length != y_data_points.length) an error is
    returned.
  -if the color argument is nil, the next color from the default theme will
    be used.
  -if you want to use a preset theme, you must set it before calling
    dataxy().

Example: 

  g = Gruff::Line.new
  g.title = "X/Y Dataset"
  g.dataxy("Apples", [1,3,4,5,6,10], [1, 2, 3, 4, 4, 3])
  g.dataxy("Bapples", [1,3,4,5,7,9], [1, 1, 2, 2, 3, 3])
  g.dataxy("Capples", [[1,1],[2,3],[3,4],[4,5],[5,7],[6,9]])
  #you can still use the old data method too if you want:
  g.data("Capples", [1, 1, 2, 2, 3, 3])
  #labels will be drawn at the x locations of the keys passed in.
  In this example the lables are drawn at x positions 2, 4, and 6:
  g.labels = {0 => '2003', 2 => '2004', 4 => '2005', 6 => '2006'}
  The 0 => '2003' label will be ignored since it is outside the chart range.

[Validate]