Add stacked line

demo/moulinrouge/__init__.py

@@ -83,7 +83,7 @@ def create_app():
                     random_value((-max, min)[random.randrange(0, 2)], max))
                           for i in range(data)]
             else:
-                values = [random_value((-max, min)[random.randrange(0, 2)],
+                values = [random_value((-max, min)[random.randrange(1, 2)],
                                        max) for i in range(data)]
             g.add(random_label(), values)
         return g.render_response()
@@ -94,8 +94,10 @@ def create_app():
         svgs = [url_for('all_svg', type=type, style=style, fill=fill)
                 for style in styles
                 for fill in (False, True)
-                for type in ('Bar', 'Line', 'XY', 'Pie', 'StackedBar',
-                          'HorizontalBar', 'HorizontalStackedBar', 'Radar')]
+                for type in ('Bar', 'Line', 'XY', 'StackedBar',
+                          'StackedLine', 'HorizontalBar',
+                          'HorizontalStackedBar',
+                          'Pie', 'Radar')]
         return render_template('svgs.jinja2',
                                svgs=svgs,
                                width=width,

demo/simple_test.py

@@ -19,7 +19,7 @@
 # along with pygal. If not, see <http://www.gnu.org/licenses/>.
 from pygal import (
     Line, Bar, XY, Pie, Radar, StackedBar, Config,
-    HorizontalBar, HorizontalStackedBar)
+    StackedLine, HorizontalBar, HorizontalStackedBar)
 from pygal.style import NeonStyle
 from math import cos, sin
 
@@ -72,16 +72,25 @@ hstackedbar.add('--->', rng3)
 with open('out-horizontalstackedbar.svg', 'w') as f:
     f.write(hstackedbar.render())
 
-line = Line(Config(y_scale=.0005))
+line = Line(Config(y_scale=.0005, fill=True, style=NeonStyle))
 rng = range(-30, 31, 5)
-line.add('test1', [1000 + cos(x / 10.) for x in rng])
-line.add('test2', [1000 + sin(x / 10.) for x in rng])
-line.add('test3', [1000 + cos(x / 10.) - sin(x / 10.) for x in rng])
+line.add('test1', [cos(x / 10.) for x in rng])
+line.add('test2', [sin(x / 10.) for x in rng])
+line.add('test3', [cos(x / 10.) - sin(x / 10.) for x in rng])
 line.x_labels = map(str, rng)
 line.title = "Line test"
 with open('out-line.svg', 'w') as f:
     f.write(line.render())
 
+stackedline = StackedLine(Config(y_scale=.0005, fill=True, style=NeonStyle))
+stackedline.add('test1', [1, 3, 2, 18, 2, 13, 8])
+stackedline.add('test2', [4, 1, 0,  1, 3, 12, 3])
+stackedline.add('test3', [9, 3, 2,  10, 8, 2, 3])
+stackedline.x_labels = map(str, ['a', 'b', 'c', 'd', 'e', 'f', 'g'])
+stackedline.title = "Stackedline test"
+with open('out-stackedline.svg', 'w') as f:
+    f.write(stackedline.render())
+
 xy = XY(Config(x_scale=1))
 xy.add('test1', [(1981, 1), (2004, 2), (2003, 10), (2012, 8), (1999, -4)])
 xy.add('test2', [(1988, -1), (1986, 12), (2007, 7), (2010, 4), (1999, 2)])

pygal/__init__.py

@@ -24,6 +24,7 @@ from pygal.graph.horizontal import HorizontalBar
 from pygal.graph.stackedbar import StackedBar
 from pygal.graph.horizontal import HorizontalStackedBar
 from pygal.graph.line import Line
+from pygal.graph.stackedline import StackedLine
 from pygal.graph.xy import XY
 from pygal.graph.pie import Pie
 from pygal.graph.radar import Radar

pygal/graph/base.py

@@ -88,6 +88,10 @@ class BaseGraph(object):
     def _values(self):
         return [val for serie in self.series for val in serie.values]
 
+    @cached_property
+    def _len(self):
+        return len(self.series[0].values)
+
     def _draw(self):
         self._compute()
         self._compute_margin()

pygal/graph/line.py

@@ -38,6 +38,11 @@ class Line(Graph):
             self.svg.node(dot, 'circle', cx=x, cy=y, r=2.5)
             self.svg.node(dot, 'text', x=x, y=y
             ).text = self._get_value(values, i)
+        if self.fill:
+            zero = self.view.y(min(max(0, self._box.ymin), self._box.ymax))
+            view_values = ([(view_values[0][0], zero)] +
+                           view_values +
+                           [(view_values[-1][0], zero)])
         self.svg.line(
             serie_node, view_values, class_='line', close=self._line_close)
 
@@ -49,9 +54,8 @@ class Line(Graph):
             self._box.ymin = min(self._values)
             self._box.ymax = max(self._values)
 
-        x_step = len(self.series[0].values)
-        self._x_pos = [x / float(x_step - 1) for x in range(x_step)
-        ] if x_step != 1 else [.5]  # Center if only one value
+        self._x_pos = [x / float(self._len - 1) for x in range(self._len)
+        ] if self._len != 1 else [.5]  # Center if only one value
         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)
 

pygal/graph/radar.py

@@ -19,7 +19,7 @@
 from pygal.graph.line import Line
 from pygal.view import PolarView
 from pygal.util import deg
-from math import cos, sin, pi
+from math import cos, pi
 
 
 class Radar(Line):

pygal/graph/stackedline.py

@@ -0,0 +1,38 @@
+# -*- coding: utf-8 -*-
+# This file is part of pygal
+#
+# A python svg graph plotting library
+# Copyright © 2012 Kozea
+#
+# This library is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation, either version 3 of the License, or (at your option) any
+# later version.
+#
+# This library is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with pygal. If not, see <http://www.gnu.org/licenses/>.
+from pygal.graph.line import Line
+
+
+class StackedLine(Line):
+    """Stacked Line graph"""
+
+    @property
+    def _values(self):
+        sums = map(sum, zip(*[serie.values for serie in self.series]))
+        return sums + super(StackedLine, self)._values
+
+    def _plot(self):
+        accumulation = map(sum, zip(*[serie.values for serie in self.series]))
+        for serie in self.series:
+            self.line(
+                self._serie(serie.index), [
+                (self._x_pos[i], v)
+                for i, v in enumerate(accumulation)])
+            accumulation = map(sum, zip(accumulation,
+                                    [-v for v in serie.values]))