# -*- 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)