#!python from itertools import chain from lxml import etree from svg.charts.graph import Graph __all__ = ('VerticalBar', 'HorizontalBar') class Bar(Graph): "A superclass for bar-style graphs. Do not instantiate directly." # gap between bars bar_gap = True # how to stack adjacent dataset series # overlap - overlap bars with transparent colors # top - stack bars on top of one another # side - stack bars side-by-side stack = 'overlap' scale_divisions = None stylesheet_names = Graph.stylesheet_names + ['bar.css'] def __init__(self, fields, *args, **kargs): self.fields = fields super(Bar, self).__init__(*args, **kargs) # adapted from Plot def get_data_values(self): min_value, max_value, scale_division = self.data_range() result = tuple(float_range(min_value, max_value + scale_division, scale_division)) if self.scale_integers: result = map(int, result) return result # adapted from plot (very much like calling data_range('y')) def data_range(self): min_value = self.data_min() max_value = self.data_max() range = max_value - min_value data_pad = range / 20.0 or 10 scale_range = (max_value + data_pad) - min_value scale_division = self.scale_divisions or (scale_range / 10.0) if self.scale_integers: scale_division = round(scale_division) or 1 return min_value, max_value, scale_division def get_field_labels(self): return self.fields def get_data_labels(self): return map(str, self.get_data_values()) def data_max(self): return max(chain(*map(lambda set: set['data'], self.data))) # above is same as # return max(map(lambda set: max(set['data']), self.data)) def data_min(self): if not getattr(self, 'min_scale_value') is None: return self.min_scale_value min_value = min(chain(*map(lambda set: set['data'], self.data))) min_value = min(min_value, 0) return min_value def get_bar_gap(self, field_size): bar_gap = 10 # default gap if field_size < 10: # adjust for narrow fields bar_gap = field_size / 2 # the following zero's out the gap if bar_gap is False bar_gap = int(self.bar_gap) * bar_gap return bar_gap def float_range(start = 0, stop = None, step = 1): "Much like the built-in function range, but accepts floats" while start < stop: yield float(start) start += step class VerticalBar(Bar): """ # === Create presentation quality SVG bar graphs easily # # = Synopsis # # require 'SVG/Graph/Bar' # # fields = %w(Jan Feb Mar); # data_sales_02 = [12, 45, 21] # # graph = SVG::Graph::Bar.new( # :height => 500, # :width => 300, # :fields => fields # ) # # graph.add_data( # :data => data_sales_02, # :title => 'Sales 2002' # ) # # print "Content-type: image/svg+xml\r\n\r\n" # print graph.burn # # = Description # # This object aims to allow you to easily create high quality # SVG[http://www.w3c.org/tr/svg bar graphs. You can either use the default # style sheet or supply your own. Either way there are many options which # can be configured to give you control over how the graph is generated - # with or without a key, data elements at each point, title, subtitle etc. # # = Notes # # The default stylesheet handles upto 12 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 12 data sets as they will have no style and # be in black. # # = Examples # # * http://germane-software.com/repositories/public/SVG/test/test.rb # # = See also # # * SVG::Graph::Graph # * SVG::Graph::BarHorizontal # * SVG::Graph::Line # * SVG::Graph::Pie # * SVG::Graph::Plot # * SVG::Graph::TimeSeries """ top_align = top_font = 1 def get_x_labels(self): return self.get_field_labels() def get_y_labels(self): return self.get_data_labels() def x_label_offset(self, width): return width / 2.0 def draw_data(self): min_value = self.data_min() unit_size = (float(self.graph_height) - self.font_size*2*self.top_font) unit_size /= (max(self.get_data_values()) - min(self.get_data_values())) bar_gap = self.get_bar_gap(self.get_field_width()) bar_width = self.get_field_width() - bar_gap if self.stack == 'side': bar_width /= len(self.data) x_mod = (self.graph_width - bar_gap)/2 if self.stack == 'side': x_mod -= bar_width/2 bottom = self.graph_height for field_count, field in enumerate(self.fields): for dataset_count, dataset in enumerate(self.data): # cases (assume 0 = +ve): # value min length # +ve +ve value - min # +ve -ve value - 0 # -ve -ve value.abs - 0 value = dataset['data'][field_count] left = self.get_field_width() * field_count length = (abs(value) - max(min_value, 0)) * unit_size # top is 0 if value is negative top = bottom - ((max(value,0) - min_value) * unit_size) if self.stack == 'side': left += bar_width * dataset_count rect = etree.SubElement(self.graph, 'rect', { 'x': str(left), 'y': str(top), 'width': str(bar_width), 'height': str(length), 'class': 'fill%s' % (dataset_count+1), }) self.make_datapoint_text(left + bar_width/2.0, top-6, value) class HorizontalBar(Bar): rotate_y_labels = True show_x_guidelines = True show_y_guidelines = False right_align = right_font = True def get_x_labels(self): return self.get_data_labels() def get_y_labels(self): return self.get_field_labels() def y_label_offset(self, height): return height / -2.0 def draw_data(self): min_value = self.data_min() unit_size = float(self.graph_width) unit_size -= self.font_size*2*self.right_font unit_size /= max(self.get_data_values()) - min(self.get_data_values()) bar_gap = self.get_bar_gap(self.get_field_height()) bar_height = self.get_field_height() - bar_gap if self.stack == 'side': bar_height /= len(self.data) y_mod = (bar_height / 2) + (self.font_size / 2) for field_count, field in enumerate(self.fields): for dataset_count, dataset in enumerate(self.data): value = dataset['data'][field_count] top = self.graph_height - (self.get_field_height() * (field_count+1)) if self.stack == 'side': top += (bar_height * dataset_count) # cases (assume 0 = +ve): # value min length left # +ve +ve value.abs - min minvalue.abs # +ve -ve value.abs - 0 minvalue.abs # -ve -ve value.abs - 0 minvalue.abs + value length = (abs(value) - max(min_value, 0)) * unit_size # left is 0 if value is negative left = (abs(min_value) + min(value, 0)) * unit_size rect = etree.SubElement(self.graph, 'rect', { 'x': str(left), 'y': str(top), 'width': str(length), 'height': str(bar_height), 'class': 'fill%s' % (dataset_count+1), }) self.make_datapoint_text(left+length+5, top+y_mod, value, "text-anchor: start; ")