Class: Gruff::Base

Inherits:
Object
  • Object
show all
Includes:
Deprecated, Magick
Defined in:
lib/gruff/base.rb

Defined Under Namespace

Modules: StackedMixin

Constant Summary collapse

DEBUG =

Draw extra lines showing where the margins and text centers are

false
DATA_LABEL_INDEX =

Used for navigating the array of data to plot

0
DATA_VALUES_INDEX =
1
DATA_COLOR_INDEX =
2
DATA_VALUES_X_INDEX =
3
LEGEND_MARGIN =

Space around text elements. Mostly used for vertical spacing

TITLE_MARGIN = 20.0
LABEL_MARGIN =
10.0
DEFAULT_MARGIN =
20.0
DEFAULT_TARGET_WIDTH =
800
THOUSAND_SEPARATOR =
','

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Deprecated

#graph_height, #graph_left, #graph_top, #graph_width, #scale_measurements, #total_height

Constructor Details

#initialize(target_width = DEFAULT_TARGET_WIDTH) ⇒ Base

If one numerical argument is given, the graph is drawn at 4/3 ratio according to the given width (800 results in 800x600, 400 gives 400x300, etc.).

Or, send a geometry string for other ratios ('800x400', '400x225').

Looks for Bitstream Vera as the default font. Expects an environment var of MAGICK_FONT_PATH to be set. (Uses RMagick's default font otherwise.)


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# File 'lib/gruff/base.rb', line 212

def initialize(target_width=DEFAULT_TARGET_WIDTH)
  if Numeric === target_width
    @columns = target_width.to_f
    @rows = target_width.to_f * 0.75
  else
    geometric_width, geometric_height = target_width.split('x')
    @columns = geometric_width.to_f
    @rows = geometric_height.to_f
  end

  initialize_ivars

  reset_themes
  self.theme = Themes::KEYNOTE
end

Instance Attribute Details

#additional_line_valuesObject

Experimental


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# File 'lib/gruff/base.rb', line 182

def additional_line_values
  @additional_line_values
end

#bottom_marginObject

Blank space below the graph


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# File 'lib/gruff/base.rb', line 49

def bottom_margin
  @bottom_margin
end

#center_labels_over_pointObject

Used internally for spacing.

By default, labels are centered over the point they represent.


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# File 'lib/gruff/base.rb', line 74

def center_labels_over_point
  @center_labels_over_point
end

#colorsObject

Get or set the list of colors that will be used to draw the bars or lines.


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# File 'lib/gruff/base.rb', line 104

def colors
  @colors
end

#fontObject

Font used for titles, labels, etc. Works best if you provide the full path to the TTF font file. RMagick must be built with the Freetype libraries for this to work properly.

Tries to find Bitstream Vera (Vera.ttf) in the location specified by ENV. Uses default RMagick font otherwise.

The font= method below fulfills the role of the writer, so we only need a reader here.


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# File 'lib/gruff/base.rb', line 118

def font
  @font
end

#font_colorObject

Returns the value of attribute font_color


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# File 'lib/gruff/base.rb', line 120

def font_color
  @font_color
end

#has_left_labelsObject

Used internally for horizontal graph types.


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# File 'lib/gruff/base.rb', line 77

def has_left_labels
  @has_left_labels
end

#hide_legendObject

Prevent drawing of the legend


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# File 'lib/gruff/base.rb', line 126

def hide_legend
  @hide_legend
end

#hide_line_markersObject

Prevent drawing of line markers


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# File 'lib/gruff/base.rb', line 123

def hide_line_markers
  @hide_line_markers
end

#hide_line_numbersObject

Prevent drawing of line numbers


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# File 'lib/gruff/base.rb', line 132

def hide_line_numbers
  @hide_line_numbers
end

#hide_titleObject

Prevent drawing of the title


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# File 'lib/gruff/base.rb', line 129

def hide_title
  @hide_title
end

#label_formattingObject

Set the number output format for labels using sprintf Default is “%.2f”


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# File 'lib/gruff/base.rb', line 199

def label_formatting
  @label_formatting
end

#label_max_sizeObject

Truncates labels if longer than max specified


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# File 'lib/gruff/base.rb', line 94

def label_max_size
  @label_max_size
end

#label_stagger_heightObject

Height of staggering between labels (Bar graph only)


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# File 'lib/gruff/base.rb', line 91

def label_stagger_height
  @label_stagger_height
end

#label_truncation_styleObject

How truncated labels visually appear if they exceed label_max_size :absolute - does not show trailing dots to indicate truncation. This is

the default.

:trailing_dots - shows trailing dots to indicate truncation (note

that label_max_size must be greater than 3).

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# File 'lib/gruff/base.rb', line 101

def label_truncation_style
  @label_truncation_style
end

#labelsObject

A hash of names for the individual columns, where the key is the array index for the column this label represents.

Not all columns need to be named.

Example: 0 => 2005, 3 => 2006, 5 => 2007, 7 => 2008


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# File 'lib/gruff/base.rb', line 69

def labels
  @labels
end

#left_marginObject

Blank space to the left of the graph


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# File 'lib/gruff/base.rb', line 55

def left_margin
  @left_margin
end

#legend_at_bottomObject

Display the legend under the graph


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# File 'lib/gruff/base.rb', line 148

def legend_at_bottom
  @legend_at_bottom
end

#legend_box_sizeObject

Optionally set the size of the colored box by each item in the legend. Default is 20.0

Will be scaled down if graph is smaller than 800px wide.


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# File 'lib/gruff/base.rb', line 191

def legend_box_size
  @legend_box_size
end

#legend_font_sizeObject

Optionally set the size of the font. Based on an 800x600px graph. Default is 20.

Will be scaled down if the graph is smaller than 800px wide.


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# File 'lib/gruff/base.rb', line 145

def legend_font_size
  @legend_font_size
end

#legend_marginObject

Blank space below the legend


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# File 'lib/gruff/base.rb', line 61

def legend_margin
  @legend_margin
end

#marker_colorObject

The color of the auxiliary lines


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# File 'lib/gruff/base.rb', line 154

def marker_color
  @marker_color
end

#marker_countObject

The number of horizontal lines shown for reference


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# File 'lib/gruff/base.rb', line 158

def marker_count
  @marker_count
end

#marker_font_sizeObject

The font size of the labels around the graph


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# File 'lib/gruff/base.rb', line 151

def marker_font_size
  @marker_font_size
end

#marker_shadow_colorObject

Returns the value of attribute marker_shadow_color


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# File 'lib/gruff/base.rb', line 155

def marker_shadow_color
  @marker_shadow_color
end

#maximum_valueObject

You can manually set a maximum value, such as a percentage-based graph that always goes to 100.

If you use this, you must set it after you have given all your data to the graph object.


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# File 'lib/gruff/base.rb', line 171

def maximum_value
  @maximum_value
end

#minimum_valueObject

You can manually set a minimum value instead of having the values guessed for you.

Set it after you have given all your data to the graph object.


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# File 'lib/gruff/base.rb', line 164

def minimum_value
  @minimum_value
end

#no_data_messageObject

Message shown when there is no data. Fits up to 20 characters. Defaults to “No Data.”


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# File 'lib/gruff/base.rb', line 136

def no_data_message
  @no_data_message
end

#right_marginObject

Blank space to the right of the graph


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# File 'lib/gruff/base.rb', line 52

def right_margin
  @right_margin
end

#show_labels_for_bar_valuesObject

Output the values for the bars on a bar graph Default is false


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# File 'lib/gruff/base.rb', line 195

def show_labels_for_bar_values
  @show_labels_for_bar_values
end

#sortObject

Set to true if you want the data sets sorted with largest avg values drawn first.


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# File 'lib/gruff/base.rb', line 175

def sort
  @sort
end

#sorted_drawingObject

Set to true if you want the data sets drawn with largest avg values drawn first. This does not affect the legend.


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# File 'lib/gruff/base.rb', line 179

def sorted_drawing
  @sorted_drawing
end

#stackedObject

Experimental


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# File 'lib/gruff/base.rb', line 185

def stacked
  @stacked
end

#titleObject

The large title of the graph displayed at the top


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# File 'lib/gruff/base.rb', line 107

def title
  @title
end

#title_font_sizeObject

The font size of the large title at the top of the graph


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# File 'lib/gruff/base.rb', line 139

def title_font_size
  @title_font_size
end

#title_marginObject

Blank space below the title


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# File 'lib/gruff/base.rb', line 58

def title_margin
  @title_margin
end

#top_marginObject

Blank space above the graph


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# File 'lib/gruff/base.rb', line 46

def top_margin
  @top_margin
end

#use_data_labelObject

With Side Bars use the data label for the marker value to the left of the bar Default is false


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# File 'lib/gruff/base.rb', line 203

def use_data_label
  @use_data_label
end

#x_axis_labelObject

A label for the bottom of the graph


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# File 'lib/gruff/base.rb', line 80

def x_axis_label
  @x_axis_label
end

#y_axis_incrementObject

Manually set increment of the horizontal marking lines


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# File 'lib/gruff/base.rb', line 88

def y_axis_increment
  @y_axis_increment
end

#y_axis_labelObject

A label for the left side of the graph


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# File 'lib/gruff/base.rb', line 83

def y_axis_label
  @y_axis_label
end

Instance Method Details

#add_color(colorname) ⇒ Object

Add a color to the list of available colors for lines.

Example:

add_color('#c0e9d3')

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# File 'lib/gruff/base.rb', line 297

def add_color(colorname)
  @colors << colorname
end

#data(name, data_points = [], color = nil) ⇒ Object

Parameters are an array where the first element is the name of the dataset and the value is an array of values to plot.

Can be called multiple times with different datasets for a multi-valued graph.

If the color argument is nil, the next color from the default theme will be used.

NOTE: If you want to use a preset theme, you must set it before calling data().

Example:

data("Bart S.", [95, 45, 78, 89, 88, 76], '#ffcc00')

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# File 'lib/gruff/base.rb', line 394

def data(name, data_points=[], color=nil)
  data_points = Array(data_points) # make sure it's an array
  @data << [name, data_points, color]
                                   # Set column count if this is larger than previous counts
  @column_count = (data_points.length > @column_count) ? data_points.length : @column_count

  # Pre-normalize
  data_points.each do |data_point|
    next if data_point.nil?

    # Setup max/min so spread starts at the low end of the data points
    if @maximum_value.nil? && @minimum_value.nil?
      @maximum_value = @minimum_value = data_point
    end

    # TODO Doesn't work with stacked bar graphs
    # Original: @maximum_value = larger_than_max?(data_point, index) ? max(data_point, index) : @maximum_value
    @maximum_value = larger_than_max?(data_point) ? data_point : @maximum_value
    @has_data = true if @maximum_value >= 0

    @minimum_value = less_than_min?(data_point) ? data_point : @minimum_value
    @has_data = true if @minimum_value < 0
  end
end

#initialize_ivarsObject

Set instance variables for this object.

Subclasses can override this, call super, then set values separately.

This makes it possible to set defaults in a subclass but still allow developers to change this values in their program.


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# File 'lib/gruff/base.rb', line 234

def initialize_ivars
  # Internal for calculations
  @raw_columns = 800.0
  @raw_rows = 800.0 * (@rows/@columns)
  @column_count = 0
  @marker_count = nil
  @maximum_value = @minimum_value = nil
  @has_data = false
  @data = Array.new
  @labels = Hash.new
  @labels_seen = Hash.new
  @sort = false
  @title = nil

  @scale = @columns / @raw_columns

  vera_font_path = File.expand_path('Vera.ttf', ENV['MAGICK_FONT_PATH'])
  @font = File.exists?(vera_font_path) ? vera_font_path : nil

  @marker_font_size = 21.0
  @legend_font_size = 20.0
  @title_font_size = 36.0

  @top_margin = @bottom_margin = @left_margin = @right_margin = DEFAULT_MARGIN
  @legend_margin = LEGEND_MARGIN
  @title_margin = TITLE_MARGIN

  @legend_box_size = 20.0

  @no_data_message = 'No Data'

  @hide_line_markers = @hide_legend = @hide_title = @hide_line_numbers = @legend_at_bottom = @show_labels_for_bar_values = false
  @center_labels_over_point = true
  @has_left_labels = false
  @label_stagger_height = 0
  @label_max_size = 0
  @label_truncation_style = :absolute

  @additional_line_values = []
  @additional_line_colors = []
  @theme_options = {}

  @x_axis_label = @y_axis_label = nil
  @y_axis_increment = nil
  @stacked = nil
  @norm_data = nil
end

#margins=(margin) ⇒ Object

Sets the top, bottom, left and right margins to margin.


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# File 'lib/gruff/base.rb', line 283

def margins=(margin)
  @top_margin = @left_margin = @right_margin = @bottom_margin = margin
end

#replace_colors(color_list = []) ⇒ Object

Replace the entire color list with a new array of colors. Also aliased as the colors= setter method.

If you specify fewer colors than the number of datasets you intend to draw, 'increment_color' will cycle through the array, reusing colors as needed.

Note that (as with the 'theme' method), you should set up your color list before you send your data (via the 'data' method). Calls to the 'data' method made prior to this call will use whatever color scheme was in place at the time data was called.

Example:

replace_colors ['#cc99cc', '#d9e043', '#34d8a2']

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# File 'lib/gruff/base.rb', line 315

def replace_colors(color_list=[])
  @colors = color_list
  @color_index = 0
end

#theme=(options) ⇒ Object

You can set a theme manually. Assign a hash to this method before you send your data.

graph.theme = {
  :colors => %w(orange purple green white red),
  :marker_color => 'blue',
  :background_colors => ['black', 'grey', :top_bottom]
}

:background_image => 'squirrel.png' is also possible.

(Or hopefully something better looking than that.)


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# File 'lib/gruff/base.rb', line 333

def theme=(options)
  reset_themes

  defaults = {
      :colors => %w(black white),
      :additional_line_colors => [],
      :marker_color => 'white',
      :marker_shadow_color => nil,
      :font_color => 'black',
      :background_colors => nil,
      :background_image => nil
  }
  @theme_options = defaults.merge options

  @colors = @theme_options[:colors]
  @marker_color = @theme_options[:marker_color]
  @marker_shadow_color = @theme_options[:marker_shadow_color]
  @font_color = @theme_options[:font_color] || @marker_color
  @additional_line_colors = @theme_options[:additional_line_colors]

  render_background
end

#theme_37signalsObject


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# File 'lib/gruff/base.rb', line 360

def theme_37signals
  self.theme = Themes::THIRTYSEVEN_SIGNALS
end

#theme_greyscaleObject


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# File 'lib/gruff/base.rb', line 376

def theme_greyscale
  self.theme = Themes::GREYSCALE
end

#theme_keynoteObject


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# File 'lib/gruff/base.rb', line 356

def theme_keynote
  self.theme = Themes::KEYNOTE
end

#theme_odeoObject


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# File 'lib/gruff/base.rb', line 368

def theme_odeo
  self.theme = Themes::ODEO
end

#theme_pastelObject


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# File 'lib/gruff/base.rb', line 372

def theme_pastel
  self.theme = Themes::PASTEL
end

#theme_rails_keynoteObject


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# File 'lib/gruff/base.rb', line 364

def theme_rails_keynote
  self.theme = Themes::RAILS_KEYNOTE
end

#to_blob(fileformat = 'PNG') ⇒ Object

Return the graph as a rendered binary blob.


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# File 'lib/gruff/base.rb', line 429

def to_blob(fileformat='PNG')
  draw
  @base_image.to_blob do
    self.format = fileformat
  end
end

#write(filename = 'graph.png') ⇒ Object

Writes the graph to a file. Defaults to 'graph.png'

Example:

write('graphs/my_pretty_graph.png')

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# File 'lib/gruff/base.rb', line 423

def write(filename='graph.png')
  draw
  @base_image.write(filename)
end