Provided initial port of the VerticalBar Graph

lib/SVG/Bar.py

@@ -0,0 +1,252 @@
+#!python
+from SVG import Graph
+from itertools import chain
+
+__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
+
+	def __init__( self, fields, *args, **kargs ):
+		self.fields = fields
+		super( Bar, self ).__init__( *args, **kargs )
+
+	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 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_css( self ):
+		return """\
+/* default fill styles for multiple datasets (probably only use a single dataset on this graph though) */
+.key1,.fill1{
+	fill: #ff0000;
+	fill-opacity: 0.5;
+	stroke: none;
+	stroke-width: 0.5px;	
+}
+.key2,.fill2{
+	fill: #0000ff;
+	fill-opacity: 0.5;
+	stroke: none;
+	stroke-width: 1px;	
+}
+.key3,.fill3{
+	fill: #00ff00;
+	fill-opacity: 0.5;
+	stroke: none;
+	stroke-width: 1px;	
+}
+.key4,.fill4{
+	fill: #ffcc00;
+	fill-opacity: 0.5;
+	stroke: none;
+	stroke-width: 1px;	
+}
+.key5,.fill5{
+	fill: #00ccff;
+	fill-opacity: 0.5;
+	stroke: none;
+	stroke-width: 1px;	
+}
+.key6,.fill6{
+	fill: #ff00ff;
+	fill-opacity: 0.5;
+	stroke: none;
+	stroke-width: 1px;	
+}
+.key7,.fill7{
+	fill: #00ffff;
+	fill-opacity: 0.5;
+	stroke: none;
+	stroke-width: 1px;	
+}
+.key8,.fill8{
+	fill: #ffff00;
+	fill-opacity: 0.5;
+	stroke: none;
+	stroke-width: 1px;	
+}
+.key9,.fill9{
+	fill: #cc6666;
+	fill-opacity: 0.5;
+	stroke: none;
+	stroke-width: 1px;	
+}
+.key10,.fill10{
+	fill: #663399;
+	fill-opacity: 0.5;
+	stroke: none;
+	stroke-width: 1px;	
+}
+.key11,.fill11{
+	fill: #339900;
+	fill-opacity: 0.5;
+	stroke: none;
+	stroke-width: 1px;	
+}
+.key12,.fill12{
+	fill: #9966FF;
+	fill-opacity: 0.5;
+	stroke: none;
+	stroke-width: 1px;	
+}
+"""
+
+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.fields
+
+	# 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
+
+		top_pad = range / 20.0 or 10
+		scale_range = ( max_value + top_pad ) - min_value
+		
+		scale_division = self.scale_divisions or ( scale_range / 10.0 )
+		
+		if self.scale_integers:
+			scale_division = scale_division.round() or 1
+			
+		return min_value, max_value, scale_division
+
+	# adapted from Plot
+	def get_data_values( self ):
+		return tuple( float_range( *self.data_range( ) ) )
+	
+	# adapted from Plot
+	def get_y_labels( self ):
+		return map( str, self.get_data_values() )
+
+	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_y_labels() ) - min( self.get_y_labels() ) )
+		
+		bar_gap = 0
+		if self.bar_gap:
+			bar_gap = 10
+			if self.get_field_width() < 10:
+				bar_gap = self.get_field_width() / 2
+
+		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() * self.field_count
+				
+				length = ( abs(value) - max( min_value, 0 ) ) * unit_size
+				# top is 0 if value is negative
+				top = bottom - (( min(value,0) - min_value ) * unit_size )
+				if self.stack == 'side':
+					left += self.bar_width * dataset_count
+
+				rect = self._create_element( 'rect', {
+					'x': str(left),
+					'y': str(top),
+					'width': str(bar_width),
+					'height': str(length),
+					'class': 'fill%s' % dataset_count+1,
+				} )
+				self.graph.appendChild( rect )
+				
+				self.make_datapoint_text( left + bar_width/2.0, top-6, value )

lib/SVG/__init__.py

@@ -136,7 +136,7 @@ Copyright © 2008 Jason R. Coombs
 		self.process_data( conf )
 		self.data.append( conf )
 
-	def validate_data( self, data ):
+	def validate_data( self, conf ):
 		try:
 			assert( isinstance( conf['data'], ( tuple, list ) ) )
 		except TypeError, e:
@@ -145,7 +145,7 @@ Copyright © 2008 Jason R. Coombs
 			if not hasattr( conf['data'], '__iter__' ):
 				raise TypeError, "conf['data'] should be tuple or list or iterable"
 
-	def process_data( data ): pass
+	def process_data( self, data ): pass
 	
 	def clear_data( self ):
 		"""This method removes all data from the object so that you can
@@ -379,12 +379,12 @@ Copyright © 2008 Jason R. Coombs
 	def get_field_width( self ):
 		return float( self.graph_width - self.font_size*2*self.right_font ) / \
 			( len( self.get_x_labels() ) - self.right_align )
-	field_width = property( get_field_width )
+	field_width = get_field_width
 	
 	def get_field_height( self ):
 		return float( self.graph_height - self.font_size*2*self.top_font ) / \
 			( len( self.get_y_labels() ) - self.top_align )
-	field_height = property( get_field_height )
+	field_height = get_field_height
 
 	def draw_y_labels( self ):
 		"Draw the Y axis labels"

test/testing.py

@@ -37,3 +37,13 @@ print g.get_x_labels()
 f = open( r'TimeSeries.py.svg', 'w' )
 f.write( res )
 f.close()
+
+from SVG import Bar
+
+g = Bar.VerticalBar(['foo','bar','baz'])
+
+g.stack = False
+
+g.add_data( { 'data': [ 1, 2, 3 ], 'title': 'series 1' } )
+
+open( r'VerticalBar.svg', 'w' ).write( g.burn() )