Uh oh!
There was an error while loading.Please reload this page.
- Notifications
You must be signed in to change notification settings - Fork7.9k
Closed as not planned
Labels
Milestone
Description
I'm currently trying to plot an HSV legend, i.e. a circle of color that becomes white as the radius goes to 0. I also posted this question onstackoverflow in the hope of getting a clever workaround.
Code:
def complex_to_rgb(complex_data, invert=False): from numpy import angle, max, pi, sin, zeros phase = angle(complex_data) amplitude = abs(complex_data) amplitude = amplitude/max(max(amplitude)) A = zeros((complex_data.shape[0], complex_data.shape[1], 3)) A[:,:,0] = .5*(sin(phase)+1)*amplitude A[:,:,1] = .5*(sin(phase+pi/2)+1)*amplitude A[:,:,2] = .5*(-sin(phase)+1)*amplitude if(invert): return 1-A else: return Aimport numpy as npfrom matplotlib.pyplot import figureN = 1024x = np.linspace(-1, 1, N)y = np.linspace(-1, 1, N)X,Y = np.meshgrid(x,y)R = np.sqrt(X*X + Y*Y)PHI = np.arctan2(Y, X)fig = figure()ax = fig.add_subplot(111, polar=True)ax.imshow(complex_to_rgb(R*np.exp(1j*PHI) * (R<1), invert=True))ax.set_xticks([-.5, 0, np.pi/2, np.pi, 3*np.pi/2])#-.5)ax.set_yticks([0, N/3, 2*N/3, N])ax.set_xticklabels(['', '$0$', r'$\pi/2$', r'$\pi$', r'$3\pi/2$'])ax.set_yticklabels([])fig.show()Problem is, if I change the -.5 xtick (e.g. to +.5), the plot gets messed up and I get division by zero warnings:
....\lib\site-packages\matplotlib\image.py:161: RuntimeWarning: divide by zero encountered in double_scalars sy = dyintv/viewlim.height....\lib\site-packages\matplotlib\image.py:190: RuntimeWarning: divide by zero encountered in double_scalars sy = dyintv/viewlim.heightI don't want the -.5 arbitrary tick mark. Why does a tick mark influence the drawing of an image?