.. _api-radar_chart: api example code: radar_chart.py ================================ .. plot:: /home/tcaswell/source/p/matplotlib/doc/mpl_examples/api/radar_chart.py :: """ Example of creating a radar chart (a.k.a. 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 def example_data(): # The following data is from the Denver Aerosol Sources and Health study. # See doi:10.1016/j.atmosenv.2008.12.017 # # The data are pollution source profile estimates for five modeled # pollution sources (e.g., cars, wood-burning, etc) that emit 7-9 chemical # species. The radar charts are experimented with here to see if we can # nicely visualize how the modeled source profiles change across four # scenarios: # 1) No gas-phase species present, just seven particulate counts on # Sulfate # Nitrate # Elemental Carbon (EC) # Organic Carbon fraction 1 (OC) # Organic Carbon fraction 2 (OC2) # Organic Carbon fraction 3 (OC3) # Pyrolized Organic Carbon (OP) # 2)Inclusion of gas-phase specie carbon monoxide (CO) # 3)Inclusion of gas-phase specie ozone (O3). # 4)Inclusion of both gas-phase speciesis present... data = [ ['Sulfate', 'Nitrate', 'EC', 'OC1', 'OC2', 'OC3', 'OP', 'CO', 'O3'], ('Basecase', [ [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]]), ('With CO', [ [0.88, 0.02, 0.02, 0.02, 0.00, 0.05, 0.00, 0.05, 0.00], [0.08, 0.94, 0.04, 0.02, 0.00, 0.01, 0.12, 0.04, 0.00], [0.01, 0.01, 0.79, 0.10, 0.00, 0.05, 0.00, 0.31, 0.00], [0.00, 0.02, 0.03, 0.38, 0.31, 0.31, 0.00, 0.59, 0.00], [0.02, 0.02, 0.11, 0.47, 0.69, 0.58, 0.88, 0.00, 0.00]]), ('With O3', [ [0.89, 0.01, 0.07, 0.00, 0.00, 0.05, 0.00, 0.00, 0.03], [0.07, 0.95, 0.05, 0.04, 0.00, 0.02, 0.12, 0.00, 0.00], [0.01, 0.02, 0.86, 0.27, 0.16, 0.19, 0.00, 0.00, 0.00], [0.01, 0.03, 0.00, 0.32, 0.29, 0.27, 0.00, 0.00, 0.95], [0.02, 0.00, 0.03, 0.37, 0.56, 0.47, 0.87, 0.00, 0.00]]), ('CO & O3', [ [0.87, 0.01, 0.08, 0.00, 0.00, 0.04, 0.00, 0.00, 0.01], [0.09, 0.95, 0.02, 0.03, 0.00, 0.01, 0.13, 0.06, 0.00], [0.01, 0.02, 0.71, 0.24, 0.13, 0.16, 0.00, 0.50, 0.00], [0.01, 0.03, 0.00, 0.28, 0.24, 0.23, 0.00, 0.44, 0.88], [0.02, 0.00, 0.18, 0.45, 0.64, 0.55, 0.86, 0.00, 0.16]]) ] return data if __name__ == '__main__': N = 9 theta = radar_factory(N, frame='polygon') data = example_data() spoke_labels = data.pop(0) fig = plt.figure(figsize=(9, 9)) fig.subplots_adjust(wspace=0.25, hspace=0.20, top=0.85, bottom=0.05) colors = ['b', 'r', 'g', 'm', 'y'] # Plot the four cases from the example data on separate axes for n, (title, case_data) in enumerate(data): ax = fig.add_subplot(2, 2, n + 1, projection='radar') plt.rgrids([0.2, 0.4, 0.6, 0.8]) ax.set_title(title, weight='bold', size='medium', position=(0.5, 1.1), horizontalalignment='center', verticalalignment='center') for d, color in zip(case_data, colors): ax.plot(theta, d, color=color) ax.fill(theta, d, facecolor=color, alpha=0.25) ax.set_varlabels(spoke_labels) # add legend relative to top-left plot plt.subplot(2, 2, 1) labels = ('Factor 1', 'Factor 2', 'Factor 3', 'Factor 4', 'Factor 5') legend = plt.legend(labels, loc=(0.9, .95), labelspacing=0.1) plt.setp(legend.get_texts(), fontsize='small') plt.figtext(0.5, 0.965, '5-Factor Solution Profiles Across Four Scenarios', ha='center', color='black', weight='bold', size='large') plt.show() Keywords: python, matplotlib, pylab, example, codex (see :ref:`how-to-search-examples`)