Source code for pygal.graph.bar

# -*- 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/>.
"""
Bar chart that presents grouped data with rectangular bars with lengths
proportional to the values that they represent.
"""

from pygal.graph.graph import Graph
from pygal.util import alter, decorate, ident, swap


[docs]class Bar(Graph): """Bar graph class""" _series_margin = .06 _serie_margin = .06 def _bar(self, serie, parent, x, y, i, zero, secondary=False): """Internal bar drawing function""" width = (self.view.x(1) - self.view.x(0)) / self._len x, y = self.view((x, y)) series_margin = width * self._series_margin x += series_margin width -= 2 * series_margin width /= self._order if self.horizontal: serie_index = self._order - serie.index - 1 else: serie_index = serie.index x += serie_index * width serie_margin = width * self._serie_margin x += serie_margin width -= 2 * serie_margin height = self.view.y(zero) - y r = serie.rounded_bars * 1 if serie.rounded_bars else 0 alter( self.svg.transposable_node( parent, 'rect', x=x, y=y, rx=r, ry=r, width=width, height=height, class_='rect reactive tooltip-trigger' ), serie.metadata.get(i) ) return x, y, width, height def _tooltip_and_print_values( self, serie_node, serie, parent, i, val, metadata, x, y, width, height ): transpose = swap if self.horizontal else ident x_center, y_center = transpose((x + width / 2, y + height / 2)) x_top, y_top = transpose((x + width, y + height)) x_bottom, y_bottom = transpose((x, y)) if self._dual: v = serie.values[i][0] else: v = serie.values[i] sign = -1 if v < self.zero else 1 self._tooltip_data( parent, val, x_center, y_center, "centered", self._get_x_label(i) ) if self.print_values_position == 'top': if self.horizontal: x = x_bottom + sign * self.style.value_font_size / 2 y = y_center else: x = x_center y = y_bottom - sign * self.style.value_font_size / 2 elif self.print_values_position == 'bottom': if self.horizontal: x = x_top + sign * self.style.value_font_size / 2 y = y_center else: x = x_center y = y_top - sign * self.style.value_font_size / 2 else: x = x_center y = y_center self._static_value(serie_node, val, x, y, metadata, "middle")
[docs] def bar(self, serie, rescale=False): """Draw a bar graph for a serie""" serie_node = self.svg.serie(serie) bars = self.svg.node(serie_node['plot'], class_="bars") if rescale and self.secondary_series: points = self._rescale(serie.points) else: points = serie.points for i, (x, y) in enumerate(points): if None in (x, y) or (self.logarithmic and y <= 0): continue metadata = serie.metadata.get(i) val = self._format(serie, i) bar = decorate( self.svg, self.svg.node(bars, class_='bar'), metadata ) x_, y_, width, height = self._bar( serie, bar, x, y, i, self.zero, secondary=rescale ) self._confidence_interval( serie_node['overlay'], x_ + width / 2, y_, serie.values[i], metadata ) self._tooltip_and_print_values( serie_node, serie, bar, i, val, metadata, x_, y_, width, height )
def _compute(self): """Compute y min and max and y scale and set labels""" if self._min: self._box.ymin = min(self._min, self.zero) if self._max: self._box.ymax = max(self._max, self.zero) self._x_pos = [ x / self._len for x in range(self._len + 1) ] if self._len > 1 else [0, 1] # Center if only one value self._points(self._x_pos) self._x_pos = [(i + .5) / self._len for i in range(self._len)] def _plot(self): """Draw bars for series and secondary series""" for serie in self.series: self.bar(serie) for serie in self.secondary_series: self.bar(serie, True)