Last active
January 6, 2017 17:34
-
-
Save afvincent/fb81d495a4b11823182af4adcf3b182c to your computer and use it in GitHub Desktop.
Some kind of MWE to bissect Matplotlib issue #7751
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| """ | |
| MWE to bissect issue #7751 | |
| ====================================== | |
| Radar chart (aka spider or star chart) | |
| ====================================== | |
| This example creates a radar chart, also known as a spider or star chart [1]_. | |
| Although this example allows a frame of either 'circle' or 'polygon', polygon | |
| frames don't have proper gridlines (the lines are circles instead of polygons). | |
| It's possible to get a polygon grid by setting GRIDLINE_INTERPOLATION_STEPS in | |
| matplotlib.axis to the desired number of vertices, but the orientation of the | |
| polygon is not aligned with the radial axes. | |
| .. [1] http://en.wikipedia.org/wiki/Radar_chart | |
| """ | |
| import numpy as np | |
| import matplotlib.pyplot as plt | |
| from matplotlib.path import Path | |
| from matplotlib.spines import Spine | |
| from matplotlib.projections.polar import PolarAxes | |
| from matplotlib.projections import register_projection | |
| def radar_factory(num_vars, frame='circle'): | |
| """Create a radar chart with `num_vars` axes. | |
| This function creates a RadarAxes projection and registers it. | |
| Parameters | |
| ---------- | |
| num_vars : int | |
| Number of variables for radar chart. | |
| frame : {'circle' | 'polygon'} | |
| Shape of frame surrounding axes. | |
| """ | |
| # calculate evenly-spaced axis angles | |
| theta = np.linspace(0, 2*np.pi, num_vars, endpoint=False) | |
| # rotate theta such that the first axis is at the top | |
| theta += np.pi/2 | |
| def draw_poly_patch(self): | |
| verts = unit_poly_verts(theta) | |
| return plt.Polygon(verts, closed=True, edgecolor='k') | |
| def draw_circle_patch(self): | |
| # unit circle centered on (0.5, 0.5) | |
| return plt.Circle((0.5, 0.5), 0.5) | |
| patch_dict = {'polygon': draw_poly_patch, 'circle': draw_circle_patch} | |
| if frame not in patch_dict: | |
| raise ValueError('unknown value for `frame`: %s' % frame) | |
| class RadarAxes(PolarAxes): | |
| name = 'radar' | |
| # use 1 line segment to connect specified points | |
| #RESOLUTION = 1 | |
| # define draw_frame method | |
| draw_patch = patch_dict[frame] | |
| def fill(self, *args, **kwargs): | |
| """Override fill so that line is closed by default""" | |
| closed = kwargs.pop('closed', True) | |
| return super(RadarAxes, self).fill(closed=closed, *args, **kwargs) | |
| def plot(self, *args, **kwargs): | |
| """Override plot so that line is closed by default""" | |
| lines = super(RadarAxes, self).plot(*args, **kwargs) | |
| for line in lines: | |
| self._close_line(line) | |
| def _close_line(self, line): | |
| x, y = line.get_data() | |
| # FIXME: markers at x[0], y[0] get doubled-up | |
| if x[0] != x[-1]: | |
| x = np.concatenate((x, [x[0]])) | |
| y = np.concatenate((y, [y[0]])) | |
| line.set_data(x, y) | |
| def set_varlabels(self, labels): | |
| self.set_thetagrids(np.degrees(theta), labels) | |
| def _gen_axes_patch(self): | |
| return self.draw_patch() | |
| def _gen_axes_spines(self): | |
| if frame == 'circle': | |
| return PolarAxes._gen_axes_spines(self) | |
| # The following is a hack to get the spines (i.e. the axes frame) | |
| # to draw correctly for a polygon frame. | |
| # spine_type must be 'left', 'right', 'top', 'bottom', or `circle`. | |
| spine_type = 'circle' | |
| verts = unit_poly_verts(theta) | |
| # close off polygon by repeating first vertex | |
| verts.append(verts[0]) | |
| path = Path(verts) | |
| spine = Spine(self, spine_type, path) | |
| spine.set_transform(self.transAxes) | |
| return {'polar': spine} | |
| register_projection(RadarAxes) | |
| return theta | |
| def unit_poly_verts(theta): | |
| """Return vertices of polygon for subplot axes. | |
| This polygon is circumscribed by a unit circle centered at (0.5, 0.5) | |
| """ | |
| x0, y0, r = [0.5] * 3 | |
| verts = [(r*np.cos(t) + x0, r*np.sin(t) + y0) for t in theta] | |
| return verts | |
| if __name__ == '__main__': | |
| N = 9 | |
| theta = radar_factory(N, frame='polygon') | |
| # Why do I need to do that? | |
| eps = 0.15 # Add > 0 epsilon to data, to avoid artifacts in log scale | |
| data = ('Basecase', np.array([ | |
| [0.88, 0.01, 0.03, 0.03, 0.00, 0.06, 0.01, 0.00, 0.00], | |
| [0.07, 0.95, 0.04, 0.05, 0.00, 0.02, 0.01, 0.00, 0.00], | |
| [0.01, 0.02, 0.85, 0.19, 0.05, 0.10, 0.00, 0.00, 0.00], | |
| [0.02, 0.01, 0.07, 0.01, 0.21, 0.12, 0.98, 0.00, 0.00], | |
| [0.01, 0.01, 0.02, 0.71, 0.74, 0.70, 0.00, 0.00, 0.00]]) + eps) | |
| spoke_labels = ['Sulfate', 'Nitrate', 'EC', 'OC1', 'OC2', 'OC3', 'OP', | |
| 'CO', 'O3'] | |
| fig, ax = plt.subplots(figsize=(9, 9), subplot_kw=dict(projection='radar')) | |
| title, case_data = data | |
| ax.set_rscale('log') # WiP: issue #7751 | |
| for d, color in zip(case_data, ['C%d' % i for i in range(len(case_data))]): | |
| ax.plot(theta, d, color=color) | |
| ax.fill(theta, d, facecolor=color, alpha=0.25) | |
| ax.set_varlabels(spoke_labels) | |
| plt.show() |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment