Source code for pygal.graph.stackedline

# -*- 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 <>.

Stacked Line chart: Like a line chart but with all lines stacking
on top of the others. Used along fill=True option.

from __future__ import division

from pygal.adapters import none_to_zero
from pygal.graph.line import Line

[docs]class StackedLine(Line): """Stacked Line graph class""" _adapters = [none_to_zero] def __init__(self, *args, **kwargs): """Custom variable initialization""" self._previous_line = None super(StackedLine, self).__init__(*args, **kwargs) def _value_format(self, value, serie, index): """ Display value and cumulation """ sum_ = serie.points[index][1] if serie in self.series and ( self.stack_from_top and self.series.index(serie) == self._order - 1 or not self.stack_from_top and self.series.index(serie) == 0): return super(StackedLine, self)._value_format(value) return '%s (+%s)' % ( self._y_format(sum_), self._y_format(value) ) def _fill(self, values): """Add extra values to fill the line""" if not self._previous_line: self._previous_line = values return super(StackedLine, self)._fill(values) new_values = values + list(reversed(self._previous_line)) self._previous_line = values return new_values def _points(self, x_pos): """ Convert given data values into drawable points (x, y) and interpolated points if interpolate option is specified """ for series_group in (self.series, self.secondary_series): accumulation = [0] * self._len for serie in series_group[::-1 if self.stack_from_top else 1]: accumulation = list(map(sum, zip(accumulation, serie.values))) serie.points = [ (x_pos[i], v) for i, v in enumerate(accumulation)] if serie.points and self.interpolate: serie.interpolated = self._interpolate(x_pos, accumulation) else: serie.interpolated = [] def _plot(self): """Plot stacked serie lines and stacked secondary lines""" for serie in self.series[::-1 if self.stack_from_top else 1]: self.line(serie) for serie in self.secondary_series[::-1 if self.stack_from_top else 1]: self.line(serie, True)