I have a radar chart. Need to change the grid from circle-form to pentagon-form. Currently, I have this output:
Whereas I expect smth like this:
Here's the info about the system i have: Windows 10 (64-bit); Python - 3.8.0 (32-bit); matplotlib - 3.3.3. This question i've seen here: How to make a polygon radar (spider) chart in python but it doesn't resolve my question. But it doesn't work for me and i can't understand why. I can simply copy the code, but the result is - outer border changes to pentagon-form, but the inner gridlines remain circular. But it works for other people!
The code of the program is below:
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.patches import Circle, RegularPolygon
from matplotlib.path import Path
from matplotlib.projections.polar import PolarAxes
from matplotlib.projections import register_projection
from matplotlib.spines import Spine
from matplotlib.transforms import Affine2D
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)
class RadarAxes(PolarAxes):
name = 'radar'
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
# rotate plot such that the first axis is at the top
self.set_theta_zero_location('N')
def fill(self, *args, closed=True, **kwargs):
"""Override fill so that line is closed by default"""
return super().fill(closed=closed, *args, **kwargs)
def plot(self, *args, **kwargs):
"""Override plot so that line is closed by default"""
lines = super().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):
# The Axes patch must be centered at (0.5, 0.5) and of radius 0.5
# in axes coordinates.
if frame == 'circle':
return Circle((0.5, 0.5), 0.5)
elif frame == 'polygon':
return RegularPolygon((0.5, 0.5), num_vars, radius=0.5, edgecolor="k")
else:
raise ValueError("unknown value for 'frame': %s" % frame)
def draw(self, renderer):
""" Draw. If frame is polygon, make gridlines polygon-shaped """
if frame == 'polygon':
gridlines = self.yaxis.get_gridlines()
for gl in gridlines:
gl.get_path()._interpolation_steps = num_vars
super().draw(renderer)
def _gen_axes_spines(self):
if frame == 'circle':
return super()._gen_axes_spines()
elif frame == 'polygon':
# spine_type must be 'left'/'right'/'top'/'bottom'/'circle'.
spine = Spine(axes=self,
spine_type='circle',
path=Path.unit_regular_polygon(num_vars))
# unit_regular_polygon gives a polygon of radius 1 centered at
# (0, 0) but we want a polygon of radius 0.5 centered at (0.5,
# 0.5) in axes coordinates.
spine.set_transform(Affine2D().scale(.5).translate(.5, .5)
+ self.transAxes)
return {'polar': spine}
else:
raise ValueError("unknown value for 'frame': %s" % frame)
register_projection(RadarAxes)
return theta
data = [['O1', 'O2', 'O3', 'O4', 'O5'],
('Title', [
[4, 3.5, 4, 2, 3,],
[1.07, 5.95, 2.04, 1.05, 0.00,],
]
)]
N = len(data[0])
theta = radar_factory(N, frame='polygon') # polygon !!!
spoke_labels = data.pop(0)
title, case_data = data[0]
fig, ax = plt.subplots(figsize=(5, 5), subplot_kw=dict(projection='radar'))
fig.subplots_adjust(top=0.85, bottom=0.05)
ax.set_rgrids([0, 1, 2.0, 3.0, 4.0, 5.0, 6])
ax.set_title(title, position=(0.5, 1.1), ha='center')
for d in case_data:
line = ax.plot(theta, d)
ax.fill(theta, d, alpha=0.25)
ax.set_varlabels(spoke_labels)
plt.show()
