Object
Used for navigating the array of data to plot
Draw extra lines showing where the margins and text centers are
Space around text elements. Mostly used for vertical spacing
Used internally for spacing.
By default, labels are centered over the point they represent.
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.
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).
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
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.
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.
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.
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.
Message shown when there is no data. Fits up to 20 characters. Defaults to “No Data.”
Set to true if you want the data sets drawn with largest avg values drawn first. This does not affect the legend.
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.)
# 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
Add a color to the list of available colors for lines.
Example:
add_color('#c0e9d3')
# File lib/gruff/base.rb, line 297 def add_color(colorname) @colors << colorname end
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')
# 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
Sets the font for graph text to the font at font_path.
# File lib/gruff/base.rb, line 288 def font=(font_path) @font = font_path @d.font = @font end
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.
# 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
Sets the top, bottom, left and right margins to margin.
# File lib/gruff/base.rb, line 283 def margins=(margin) @top_margin = @left_margin = @right_margin = @bottom_margin = margin end
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']
# File lib/gruff/base.rb, line 315 def replace_colors(color_list=[]) @colors = color_list @color_index = 0 end
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.)
# File lib/gruff/base.rb, line 333 def theme=(options) reset_themes defaults = { :colors => %(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
# File lib/gruff/base.rb, line 360 def theme_37signals self.theme = Themes::THIRTYSEVEN_SIGNALS end
# File lib/gruff/base.rb, line 376 def theme_greyscale self.theme = Themes::GREYSCALE end
# File lib/gruff/base.rb, line 356 def theme_keynote self.theme = Themes::KEYNOTE end
# File lib/gruff/base.rb, line 368 def theme_odeo self.theme = Themes::ODEO end
# File lib/gruff/base.rb, line 372 def theme_pastel self.theme = Themes::PASTEL end
# File lib/gruff/base.rb, line 364 def theme_rails_keynote self.theme = Themes::RAILS_KEYNOTE end
Return a calculation of center
# File lib/gruff/base.rb, line 715 def center(size) (@raw_columns - size) / 2 end
Overridden by subclasses to do the actual plotting of the graph.
Subclasses should start by calling super() for this method.
# File lib/gruff/base.rb, line 442 def draw # Maybe should be done in one of the following functions for more granularity. unless @has_data draw_no_data return end setup_data setup_drawing debug { # Outer margin @d.rectangle(@left_margin, @top_margin, @raw_columns - @right_margin, @raw_rows - @bottom_margin) # Graph area box @d.rectangle(@graph_left, @graph_top, @graph_right, @graph_bottom) } draw_legend draw_line_markers draw_axis_labels draw_title end
Draw the optional labels for the x axis and y axis.
# File lib/gruff/base.rb, line 580 def draw_axis_labels unless @x_axis_label.nil? # X Axis # Centered vertically and horizontally by setting the # height to 1.0 and the width to the width of the graph. x_axis_label_y_coordinate = @graph_bottom + LABEL_MARGIN * 2 + @marker_caps_height # TODO Center between graph area @d.fill = @font_color @d.font = @font if @font @d.stroke('transparent') @d.pointsize = scale_fontsize(@marker_font_size) @d.gravity = NorthGravity @d = @d.annotate_scaled(@base_image, @raw_columns, 1.0, 0.0, x_axis_label_y_coordinate, @x_axis_label, @scale) debug { @d.line 0.0, x_axis_label_y_coordinate, @raw_columns, x_axis_label_y_coordinate } end unless @y_axis_label.nil? # Y Axis, rotated vertically @d.rotation = -90.0 @d.gravity = CenterGravity @d = @d.annotate_scaled(@base_image, 1.0, @raw_rows, @left_margin + @marker_caps_height / 2.0, 0.0, @y_axis_label, @scale) @d.rotation = 90.0 end end
Draws column labels below graph, centered over x_offset
# File lib/gruff/base.rb, line 816 def draw_label(x_offset, index) return if @hide_line_markers if !@labels[index].nil? && @labels_seen[index].nil? y_offset = @graph_bottom + LABEL_MARGIN # TESTME # FIXME: Consider chart types other than bar # TODO: See if index.odd? is the best stragegy y_offset += @label_stagger_height if index.odd? label_text = @labels[index] # TESTME # FIXME: Consider chart types other than bar if label_text.size > @label_max_size if @label_truncation_style == :trailing_dots if @label_max_size > 3 # 4 because '...' takes up 3 chars label_text = "#{label_text[0 .. (@label_max_size - 4)]}..." end else # @label_truncation_style is :absolute (default) label_text = label_text[0 .. (@label_max_size - 1)] end end if x_offset >= @graph_left && x_offset <= @graph_right @d.fill = @font_color @d.font = @font if @font @d.stroke('transparent') @d.font_weight = NormalWeight @d.pointsize = scale_fontsize(@marker_font_size) @d.gravity = NorthGravity @d = @d.annotate_scaled(@base_image, 1.0, 1.0, x_offset, y_offset, label_text, @scale) end @labels_seen[index] = 1 debug { @d.line 0.0, y_offset, @raw_columns, y_offset } end end
Draws a legend with the names of the datasets matched to the colors used to draw them.
# File lib/gruff/base.rb, line 723 def draw_legend return if @hide_legend @legend_labels = @data.collect { |item| item[DATA_LABEL_INDEX] } legend_square_width = @legend_box_size # small square with color of this item # May fix legend drawing problem at small sizes @d.font = @font if @font @d.pointsize = @legend_font_size label_widths = [[]] # Used to calculate line wrap @legend_labels.each do |label| metrics = @d.get_type_metrics(@base_image, label.to_s) label_width = metrics.width + legend_square_width * 2.7 label_widths.last.push label_width if sum(label_widths.last) > (@raw_columns * 0.9) label_widths.push [label_widths.last.pop] end end current_x_offset = center(sum(label_widths.first)) current_y_offset = @legend_at_bottom ? @graph_height + title_margin : (@hide_title ? @top_margin + title_margin : @top_margin + title_margin + @title_caps_height) @legend_labels.each_with_index do |legend_label, index| # Draw label @d.fill = @font_color @d.font = @font if @font @d.pointsize = scale_fontsize(@legend_font_size) @d.stroke('transparent') @d.font_weight = NormalWeight @d.gravity = WestGravity @d = @d.annotate_scaled(@base_image, @raw_columns, 1.0, current_x_offset + (legend_square_width * 1.7), current_y_offset, legend_label.to_s, @scale) # Now draw box with color of this dataset @d = @d.stroke('transparent') @d = @d.fill @data[index][DATA_COLOR_INDEX] @d = @d.rectangle(current_x_offset, current_y_offset - legend_square_width / 2.0, current_x_offset + legend_square_width, current_y_offset + legend_square_width / 2.0) @d.pointsize = @legend_font_size metrics = @d.get_type_metrics(@base_image, legend_label.to_s) current_string_offset = metrics.width + (legend_square_width * 2.7) # Handle wrapping label_widths.first.shift if label_widths.first.empty? debug { @d.line 0.0, current_y_offset, @raw_columns, current_y_offset } label_widths.shift current_x_offset = center(sum(label_widths.first)) unless label_widths.empty? line_height = [@legend_caps_height, legend_square_width].max + legend_margin if label_widths.length > 0 # Wrap to next line and shrink available graph dimensions current_y_offset += line_height @graph_top += line_height @graph_height = @graph_bottom - @graph_top end else current_x_offset += current_string_offset end end @color_index = 0 end
Draws horizontal background lines and labels
# File lib/gruff/base.rb, line 613 def draw_line_markers return if @hide_line_markers @d = @d.stroke_antialias false if @y_axis_increment.nil? # Try to use a number of horizontal lines that will come out even. # # TODO Do the same for larger numbers...100, 75, 50, 25 if @marker_count.nil? (3..7).each do |lines| if @spread % lines == 0.0 @marker_count = lines break end end @marker_count ||= 4 end @increment = (@spread > 0 && @marker_count > 0) ? significant(@spread / @marker_count) : 1 else # TODO Make this work for negative values @marker_count = (@spread / @y_axis_increment).to_i @increment = @y_axis_increment end @increment_scaled = @graph_height.to_f / (@spread / @increment) # Draw horizontal line markers and annotate with numbers (0..@marker_count).each do |index| y = @graph_top + @graph_height - index.to_f * @increment_scaled @d = @d.fill(@marker_color) # FIXME(uwe): Workaround for Issue #66 # https://github.com/topfunky/gruff/issues/66 # https://github.com/rmagick/rmagick/issues/82 # Remove if the issue gets fixed. y += 0.001 unless defined?(JRUBY_VERSION) # EMXIF @d = @d.line(@graph_left, y, @graph_right, y) #If the user specified a marker shadow color, draw a shadow just below it unless @marker_shadow_color.nil? @d = @d.fill(@marker_shadow_color) @d = @d.line(@graph_left, y + 1, @graph_right, y + 1) end marker_label = BigDecimal(index.to_s) * BigDecimal(@increment.to_s) + BigDecimal(@minimum_value.to_s) unless @hide_line_numbers @d.fill = @font_color @d.font = @font if @font @d.stroke('transparent') @d.pointsize = scale_fontsize(@marker_font_size) @d.gravity = EastGravity # Vertically center with 1.0 for the height @d = @d.annotate_scaled(@base_image, @graph_left - LABEL_MARGIN, 1.0, 0.0, y, label(marker_label, @increment), @scale) end end # # Submitted by a contibutor...the utility escapes me # i = 0 # @additional_line_values.each do |value| # @increment_scaled = @graph_height.to_f / (@maximum_value.to_f / value) # # y = @graph_top + @graph_height - @increment_scaled # # @d = @d.stroke(@additional_line_colors[i]) # @d = @d.line(@graph_left, y, @graph_right, y) # # # @d.fill = @additional_line_colors[i] # @d.font = @font if @font # @d.stroke('transparent') # @d.pointsize = scale_fontsize(@marker_font_size) # @d.gravity = EastGravity # @d = @d.annotate_scaled( @base_image, # 100, 20, # -10, y - (@marker_font_size/2.0), # "", @scale) # i += 1 # end @d = @d.stroke_antialias true end
Shows an error message because you have no data.
# File lib/gruff/base.rb, line 881 def draw_no_data @d.fill = @font_color @d.font = @font if @font @d.stroke('transparent') @d.font_weight = NormalWeight @d.pointsize = scale_fontsize(80) @d.gravity = CenterGravity @d = @d.annotate_scaled(@base_image, @raw_columns, @raw_rows/2.0, 0, 10, @no_data_message, @scale) end
Draws a title on the graph.
# File lib/gruff/base.rb, line 798 def draw_title return if (@hide_title || @title.nil?) @d.fill = @font_color @d.font = @font if @font @d.stroke('transparent') @d.pointsize = scale_fontsize(@title_font_size) @d.font_weight = BoldWeight @d.gravity = NorthGravity @d = @d.annotate_scaled(@base_image, @raw_columns, 1.0, 0, @top_margin, @title, @scale) end
Draws the data value over the data point in bar graphs
# File lib/gruff/base.rb, line 861 def draw_value_label(x_offset, y_offset, data_point, bar_value=false) return if @hide_line_markers && !bar_value #y_offset = @graph_bottom + LABEL_MARGIN @d.fill = @font_color @d.font = @font if @font @d.stroke('transparent') @d.font_weight = NormalWeight @d.pointsize = scale_fontsize(@marker_font_size) @d.gravity = NorthGravity @d = @d.annotate_scaled(@base_image, 1.0, 1.0, x_offset, y_offset, data_point.to_s, @scale) debug { @d.line 0.0, y_offset, @raw_columns, y_offset } end
Used by StackedBar and child classes.
May need to be moved to the StackedBar class.
# File lib/gruff/base.rb, line 1025 def get_maximum_by_stack # Get sum of each stack max_hash = {} @data.each do |data_set| data_set[DATA_VALUES_INDEX].each_with_index do |data_point, i| max_hash[i] = 0.0 unless max_hash[i] max_hash[i] += data_point.to_f end end # @maximum_value = 0 max_hash.keys.each do |key| @maximum_value = max_hash[key] if max_hash[key] > @maximum_value end @minimum_value = 0 end
Make copy of data with values scaled between 0-100
# File lib/gruff/base.rb, line 490 def normalize(force=false) if @norm_data.nil? || force @norm_data = [] return unless @has_data @data.each do |data_row| norm_data_points = [] data_row[DATA_VALUES_INDEX].each do |data_point| if data_point.nil? norm_data_points << nil else norm_data_points << ((data_point.to_f - @minimum_value.to_f) / @spread) end end if @show_labels_for_bar_values @norm_data << [data_row[DATA_LABEL_INDEX], norm_data_points, data_row[DATA_COLOR_INDEX], data_row[DATA_VALUES_INDEX]] else @norm_data << [data_row[DATA_LABEL_INDEX], norm_data_points, data_row[DATA_COLOR_INDEX]] end end end end
Finds the best background to render based on the provided theme options.
Creates a @base_image to draw on.
# File lib/gruff/base.rb, line 897 def render_background case @theme_options[:background_colors] when Array @base_image = render_gradiated_background(@theme_options[:background_colors][0], @theme_options[:background_colors][1], @theme_options[:background_direction]) when String @base_image = render_solid_background(@theme_options[:background_colors]) else @base_image = render_image_background(*@theme_options[:background_image]) end end
Use with a theme definition method to draw a gradiated background.
# File lib/gruff/base.rb, line 916 def render_gradiated_background(top_color, bottom_color, direct = :top_bottom) case direct when :bottom_top gradient_fill = GradientFill.new(0, 0, 100, 0, bottom_color, top_color) when :left_right gradient_fill = GradientFill.new(0, 0, 0, 100, top_color, bottom_color) when :right_left gradient_fill = GradientFill.new(0, 0, 0, 100, bottom_color, top_color) when :topleft_bottomright gradient_fill = GradientFill.new(0, 100, 100, 0, top_color, bottom_color) when :topright_bottomleft gradient_fill = GradientFill.new(0, 0, 100, 100, bottom_color, top_color) else gradient_fill = GradientFill.new(0, 0, 100, 0, top_color, bottom_color) end Image.new(@columns, @rows, gradient_fill) end
Use with a theme to use an image (800x600 original) background.
# File lib/gruff/base.rb, line 935 def render_image_background(image_path) image = Image.read(image_path) if @scale != 1.0 image[0].resize!(@scale) # TODO Resize with new scale (crop if necessary for wide graph) end image[0] end
Make a new image at the current size with a solid color.
# File lib/gruff/base.rb, line 909 def render_solid_background(color) Image.new(@columns, @rows) { self.background_color = color } end
Use with a theme to make a transparent background
# File lib/gruff/base.rb, line 944 def render_transparent_background Image.new(@columns, @rows) do self.background_color = 'transparent' end end
Resets everything to defaults (except data).
# File lib/gruff/base.rb, line 951 def reset_themes @color_index = 0 @labels_seen = {} @theme_options = {} @d = Draw.new # Scale down from 800x600 used to calculate drawing. @d = @d.scale(@scale, @scale) end
Return a comparable fontsize for the current graph.
# File lib/gruff/base.rb, line 966 def scale_fontsize(value) value * @scale end
Set the color for each data set unless it was gived in the data(…) call.
# File lib/gruff/base.rb, line 1011 def set_colors @data.each { |a| a[DATA_COLOR_INDEX] ||= increment_color } end
Calculates size of drawable area and generates normalized data.
line markers
legend
title
# File lib/gruff/base.rb, line 480 def setup_drawing calculate_spread sort_data if @sort # Sort data with avg largest values set first (for display) set_colors normalize setup_graph_measurements sort_norm_data if @sorted_drawing # Sort norm_data with avg largest values set first (for display) end
Calculates size of drawable area, general font dimensions, etc.
# File lib/gruff/base.rb, line 521 def setup_graph_measurements @marker_caps_height = @hide_line_markers ? 0 : calculate_caps_height(@marker_font_size) @title_caps_height = (@hide_title || @title.nil?) ? 0 : calculate_caps_height(@title_font_size) * @title.lines.to_a.size @legend_caps_height = @hide_legend ? 0 : calculate_caps_height(@legend_font_size) if @hide_line_markers (@graph_left, @graph_right_margin, @graph_bottom_margin) = [@left_margin, @right_margin, @bottom_margin] else if @has_left_labels longest_left_label_width = calculate_width(@marker_font_size, labels.values.inject('') { |value, memo| (value.to_s.length > memo.to_s.length) ? value : memo }) * 1.25 else longest_left_label_width = calculate_width(@marker_font_size, label(@maximum_value.to_f, @increment)) end # Shift graph if left line numbers are hidden line_number_width = @hide_line_numbers && !@has_left_labels ? 0.0 : (longest_left_label_width + LABEL_MARGIN * 2) @graph_left = @left_margin + line_number_width + (@y_axis_label.nil? ? 0.0 : @marker_caps_height + LABEL_MARGIN * 2) # Make space for half the width of the rightmost column label. # Might be greater than the number of columns if between-style bar markers are used. last_label = @labels.keys.sort.last.to_i extra_room_for_long_label = (last_label >= (@column_count-1) && @center_labels_over_point) ? calculate_width(@marker_font_size, @labels[last_label]) / 2.0 : 0 @graph_right_margin = @right_margin + extra_room_for_long_label @graph_bottom_margin = @bottom_margin + @marker_caps_height + LABEL_MARGIN end @graph_right = @raw_columns - @graph_right_margin @graph_width = @raw_columns - @graph_left - @graph_right_margin # When @hide title, leave a title_margin space for aesthetics. # Same with @hide_legend @graph_top = @legend_at_bottom ? @top_margin : (@top_margin + (@hide_title ? title_margin : @title_caps_height + title_margin) + (@hide_legend ? legend_margin : @legend_caps_height + legend_margin)) x_axis_label_height = @x_axis_label.nil? ? 0.0 : @marker_caps_height + LABEL_MARGIN # FIXME: Consider chart types other than bar @graph_bottom = @raw_rows - @graph_bottom_margin - x_axis_label_height - @label_stagger_height @graph_height = @graph_bottom - @graph_top end
Sort with largest overall summed value at front of array.
# File lib/gruff/base.rb, line 1006 def sort_data @data = @data.sort_by { |a| -a[DATA_VALUES_INDEX].inject(0) { |sum, num| sum + num.to_f } } end
Sort with largest overall summed value at front of array so it shows up correctly in the drawn graph.
# File lib/gruff/base.rb, line 1017 def sort_norm_data @norm_data = @norm_data.sort_by { |a| -a[DATA_VALUES_INDEX].inject(0) { |sum, num| sum + num.to_f } } end
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