Start working on radar

out.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 from pygal import (
-    Line, Bar, XY, Pie, StackedBar, Config,
+    Line, Bar, XY, Pie, Radar, StackedBar, Config,
     HorizontalBar, HorizontalStackedBar)
 from pygal.style import NeonStyle
 from math import cos, sin
@@ -80,3 +80,14 @@ pie.add('test2', 29)
 pie.title = "Pie test"
 with open('out-pie.svg', 'w') as f:
     f.write(pie.render())
+
+config = Config()
+config.x_labels = (
+    'black', 'red', 'blue', 'yellow', 'orange', 'green', 'white')
+radar = Radar(config)
+radar.add('test', [9, 10, 3, 5, 7, 2, 5])
+radar.add('test2', [10, 2, 0, 5, 1, 9, 4])
+
+radar.title = "Radar test"
+with open('out-radar.svg', 'w') as f:
+    f.write(radar.render())

pygal/__init__.py

@@ -7,4 +7,5 @@ from pygal.graph.horizontal import HorizontalStackedBar
 from pygal.graph.line import Line
 from pygal.graph.xy import XY
 from pygal.graph.pie import Pie
+from pygal.graph.radar import Radar
 from pygal.config import Config

pygal/graph/radar.py

@@ -0,0 +1,27 @@
+from pygal.graph.base import BaseGraph
+from math import pi
+
+
+class Radar(BaseGraph):
+    """Kiviat graph"""
+
+    def _compute(self):
+        vals = [val for serie in self.series for val in serie.values]
+        self._box.ymax = 2 * max(vals)
+        self._box.ymin = - self._box.ymax
+        self._box.xmin = self._box.ymin
+        self._box.xmax = self._box.ymax
+
+        delta = 2 * pi / float(len(self.x_labels))
+        x_step = len(self.series[0].values)
+        self._x_pos = [.5 * pi - i * delta for i in range(x_step)]
+        self._y_pos = self._pos(self._box.ymin, self._box.ymax, self.y_scale
+        ) if not self.y_labels else map(int, self.y_labels)
+        self._x_labels = self.x_labels and zip(self.x_labels, self._x_pos)
+        self._y_labels = zip(map(str, self._y_pos), self._y_pos)
+
+    def _plot(self):
+        for serie in self.series:
+            serie_node = self.svg.serie(serie.index)
+            # self.svg.web(serie_node, serie,
+                         # [val / float(self._rmax) for val in serie.values])

pygal/svg.py

@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 import os
 from lxml import etree
 from pygal.view import View
@@ -20,7 +21,8 @@ class Svg(object):
                 None: self.ns,
                 'xlink': 'http://www.w3.org/1999/xlink',
             })
-
+        self.root.append(etree.Comment(u'Generated with pygal ©Kozea 2012'))
+        self.root.append(etree.Comment(u'http://github.com/Kozea/pygal'))
         self.defs = self.node(tag='defs')
         self.add_style(self.graph.base_css or os.path.join(
             os.path.dirname(__file__), 'css', 'graph.css'))
@@ -133,6 +135,22 @@ class Svg(object):
                     self.graph.y_label_rotation, x, y)
             text.text = label
 
+    def web_axis(self):
+        axis = self.node(self.plot, class_="axis polar")
+        delta = 2 * pi / float(len(self.graph.x_labels))
+        center = self.view((0, 0))
+        f = lambda x: '%f %f' % x
+        for i, title in enumerate(self.graph.x_labels):
+            angle = .5 * pi - i * delta
+            end = self.view((cos(angle), sin(angle)))
+            self.node(axis, 'path',
+                      d='M%s L%s' % (f(center), f(end)),
+                      class_='line')
+            self.node(axis, 'text',
+                      x=end[0],
+                      y=end[1]
+            ).text = str(i)
+
     def legend(self):
         if not self.graph.show_legend:
             return
@@ -265,6 +283,18 @@ class Svg(object):
                   y=center[1] - text_r * sin(text_angle),
               ).text = '{:.2%}'.format(perc)
 
+    def web(self, serie_node, serie, radius):
+        webs = self.node(serie_node, class_="webs")
+        web = self.node(webs, class_="web")
+        # view_radius = map(self.view, radius)
+        origin = '%f %f' % self.view((0, 0))
+        dot1 = '%f %f' % self.view((1, 1))
+        dot2 = '%f %f' % self.view((-1, -1))
+        self.node(web, 'path',
+                  d='M%s L%s %s' % (
+                      origin, dot1, dot2),
+                  class_='web')
+
     def render(self):
         return etree.tostring(
             self.root, pretty_print=True,