Remove the jaggedness

user_2749397 0
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I'm trying to plot a Spirograph™ curve

In [65]: from matplotlib.pyplot import gca, subplots
    ...: from numpy import exp, lcm, linspace, pi
    ...: 
    ...: def prepare_for_sg():
    ...:     fig, ax = subplots()
    ...:     ax.set_aspect(1)
    ...:     ax.axis(False)
    ...:     return fig, ax
    ...: 
    ...: def plot_sg(R, r, d, Φ=0.0, φ=0.0, ax=None):
    ...:     if ax is None : ax = gca()
    ...:     Ω = 2*pi ;  ω = -Ω*R/r
    ...:     n = lcm(r, R)
    ...:     t = linspace(0, n, n*360+1)
    ...:     xy = (R-r)*np.exp(1j*Ω*(t-Φ)) + d*np.exp(1j*ω*(t-φ))
    ...:     line, = ax.plot(xy.real, xy.imag)
    ...:     line.set_antialiased(True)
    ...: 
    ...: prepare_for_sg() ; plot_sg(56, 42, 13)

In [66]: !xmag

and below it's what I get, plus an xmag window zooming on a detail of the curve — there is no excess of antialiasing.

What should I do to remove the jaggedness?

EDIT
Having changed my glasses, I recognize that there is a very little bit of antialiasing (thanks @Thomas).
With respect to Thomas's hint, reducing the density of points, I reduced the number of points by a factor of 12 (from 360 per lobe to 30) but I haven't seen any improvement on the smoothness of the curve (there is the same tiny little bit of antialiasing), on the contrary there is a sensible degradation of the curve rendering as a whole.

What should I do to increase the aggressiveness of antialiasing?

enter image description here

matplotlib antialiasing python
2 Answers

matplotlib renders the graph for your screen, so in the end, this is like a bitmap. There will always be some form aliasing in this case.

I assume you want a graph without aliasing to process it further, maybe printing it with high detail? Then you could plt.savefig("output.pdf"), which would save it as PDF with vector graphics.

user_99469870

try to modify figure size and linewidth

    line, = ax.plot(xy.real, xy.imag,linewidth=5.0) #line width
    fig = plt.gcf()
    fig.set_size_inches(30, 30) #set figure size

example

user_178643210
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