Source code for pygal.graph.pie

# -*- coding: utf-8 -*-
# This file is part of pygal
#
# A python svg graph plotting library
# Copyright © 2012-2016 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/>.
"""
Pie chart: A circular chart divided into slice to illustrate proportions
It can be made as a donut or a half pie.
"""

from __future__ import division

from math import pi

from pygal.adapters import none_to_zero, positive
from pygal.graph.graph import Graph
from pygal.util import alter, decorate


[docs]class Pie(Graph): """Pie graph class""" _adapters = [positive, none_to_zero]
[docs] def slice(self, serie, start_angle, total): """Make a serie slice""" serie_node = self.svg.serie(serie) dual = self._len > 1 and not self._order == 1 slices = self.svg.node(serie_node['plot'], class_="slices") serie_angle = 0 original_start_angle = start_angle if self.half_pie: center = ((self.width - self.margin_box.x) / 2., (self.height - self.margin_box.y) / 1.25) else: center = ((self.width - self.margin_box.x) / 2., (self.height - self.margin_box.y) / 2.) radius = min(center) for i, val in enumerate(serie.values): perc = val / total if self.half_pie: angle = 2 * pi * perc / 2 else: angle = 2 * pi * perc serie_angle += angle val = self._format(serie, i) metadata = serie.metadata.get(i) slice_ = decorate( self.svg, self.svg.node(slices, class_="slice"), metadata) if dual: small_radius = radius * .9 big_radius = radius else: big_radius = radius * .9 small_radius = radius * serie.inner_radius alter(self.svg.slice( serie_node, slice_, big_radius, small_radius, angle, start_angle, center, val, i, metadata), metadata) start_angle += angle if dual: val = self._serie_format(serie, sum(serie.values)) self.svg.slice(serie_node, self.svg.node(slices, class_="big_slice"), radius * .9, 0, serie_angle, original_start_angle, center, val, i, metadata) return serie_angle
def _compute_x_labels(self): pass def _compute_y_labels(self): pass def _plot(self): """Draw all the serie slices""" total = sum(map(sum, map(lambda x: x.values, self.series))) if total == 0: return if self.half_pie: current_angle = 3*pi/2 else: current_angle = 0 for index, serie in enumerate(self.series): angle = self.slice(serie, current_angle, total) current_angle += angle