Source code for pygal.graph.gauge

# -*- 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 <>.

"""Gauge chart representing values as needles on a polar scale"""

from __future__ import division

from pygal._compat import is_str
from pygal.graph.graph import Graph
from pygal.util import alter, compute_scale, cut, decorate
from pygal.view import PolarThetaLogView, PolarThetaView

[docs]class Gauge(Graph): """Gauge graph class""" needle_width = 1 / 20 def _set_view(self): """Assign a view to current graph""" if self.logarithmic: view_class = PolarThetaLogView else: view_class = PolarThetaView self.view = view_class( self.width - self.margin_box.x, self.height - self.margin_box.y, self._box)
[docs] def needle(self, serie): """Draw a needle for each value""" serie_node = self.svg.serie(serie) for i, theta in enumerate(serie.values): if theta is None: continue def point(x, y): return '%f %f' % self.view((x, y)) val = self._format(serie, i) metadata = serie.metadata.get(i) gauges = decorate( self.svg, self.svg.node(serie_node['plot'], class_="dots"), metadata) tolerance = 1.15 if theta < self._min: theta = self._min * tolerance if theta > self._max: theta = self._max * tolerance w = (self._box._tmax - self._box._tmin + self.view.aperture) / 4 if self.logarithmic: w = min(w, self._min - self._min * 10 ** -10) alter( self.svg.node( gauges, 'path', d='M %s L %s A %s 1 0 1 %s Z' % ( point(.85, theta), point(self.needle_width, theta - w), '%f %f' % (self.needle_width, self.needle_width), point(self.needle_width, theta + w), ), class_='line reactive tooltip-trigger'), metadata) x, y = self.view((.75, theta)) self._tooltip_data( gauges, val, x, y, xlabel=self._get_x_label(i)) self._static_value(serie_node, val, x, y, metadata)
def _y_axis(self, draw_axes=True): """Override y axis to plot a polar axis""" axis = self.svg.node(self.nodes['plot'], class_="axis x gauge") for i, (label, theta) in enumerate(self._y_labels): guides = self.svg.node(axis, class_='guides') self.svg.line( guides, [self.view((.95, theta)), self.view((1, theta))], close=True, class_='line') self.svg.line( guides, [self.view((0, theta)), self.view((.95, theta))], close=True, class_='guide line %s' % ( 'major' if i in (0, len(self._y_labels) - 1) else '')) x, y = self.view((.9, theta)) self.svg.node( guides, 'text', x=x, y=y ).text = label self.svg.node( guides, 'title', ).text = self._y_format(theta) def _x_axis(self, draw_axes=True): """Override x axis to put a center circle in center""" axis = self.svg.node(self.nodes['plot'], class_="axis y gauge") x, y = self.view((0, 0)) self.svg.node(axis, 'circle', cx=x, cy=y, r=4) def _compute(self): """Compute y min and max and y scale and set labels""" self.min_ = self._min or 0 self.max_ = self._max or 0 if self.max_ - self.min_ == 0: self.min_ -= 1 self.max_ += 1 self._box.set_polar_box( 0, 1, self.min_, self.max_) def _compute_x_labels(self): pass def _compute_y_labels(self): y_pos = compute_scale( self.min_, self.max_, self.logarithmic, self.order_min, self.min_scale, self.max_scale ) if self.y_labels: self._y_labels = [] for i, y_label in enumerate(self.y_labels): if isinstance(y_label, dict): pos = self._adapt(y_label.get('value')) title = y_label.get('label', self._y_format(pos)) elif is_str(y_label): pos = self._adapt(y_pos[i]) title = y_label else: pos = self._adapt(y_label) title = self._y_format(pos) self._y_labels.append((title, pos)) self.min_ = min(self.min_, min(cut(self._y_labels, 1))) self.max_ = max(self.max_, max(cut(self._y_labels, 1))) self._box.set_polar_box( 0, 1, self.min_, self.max_) else: self._y_labels = list(zip(map(self._y_format, y_pos), y_pos)) def _plot(self): """Plot all needles""" for serie in self.series: self.needle(serie)