Created
March 9, 2012 21:12
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How to plot nice 2d density plots of samples in python
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| import numpy as np | |
| import scipy.special as sp | |
| from matplotlib.colors import LinearSegmentedColormap | |
| import matplotlib.cm as cm | |
| import matplotlib.pyplot as pl | |
| def reshist2d(x, y, *args, **kwargs): | |
| ax = kwargs.pop('ax', pl.gca()) | |
| extent = kwargs.pop('extent', [[x.min(), x.max()], [y.min(), y.max()]]) | |
| bins = kwargs.pop('bins', 50) | |
| color = kwargs.pop('color', 'k') | |
| cmap = cm.get_cmap('gray') | |
| cmap._init() | |
| cmap._lut[:-3,:-1] = 0. | |
| cmap._lut[:-3, -1] = np.linspace(1,0,cmap.N) | |
| X = np.linspace(extent[0][0], extent[0][1], bins+1) | |
| Y = np.linspace(extent[1][0], extent[1][1], bins+1) | |
| H, X, Y = np.histogram2d(x.flatten(), y.flatten(), bins=(X,Y)) | |
| V = sp.erf(np.arange(0.5, 2.1, 0.5)/np.sqrt(2)) | |
| Hflat = H.flatten() | |
| inds = np.argsort(Hflat)[::-1] | |
| Hflat = Hflat[inds] | |
| sm = np.cumsum(Hflat) | |
| sm /= sm[-1] | |
| for i, v0 in enumerate(V): | |
| try: | |
| V[i] = Hflat[sm <= v0][-1] | |
| except: | |
| V[i] = Hflat[0] | |
| X, Y = 0.5*(X[1:]+X[:-1]), 0.5*(Y[1:]+Y[:-1]) | |
| ax.plot(x, y, 'o', color=color, ms=1.5, zorder=-1, alpha=0.1, | |
| rasterized=True) | |
| ax.contourf(X, Y, H.T, [V[-1], 0.], | |
| cmap=LinearSegmentedColormap.from_list('cmap',([1]*3,[1]*3),N=2)) | |
| ax.pcolor(X, Y, H.max()-H.T, cmap=cmap) | |
| ax.contour(X, Y, H.T, V, colors=color) |
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Dude, are you going to merge this with the plotting in pappy, or are we going to make a separate plotting package built on matplotlib for plotting samples and PDFs inferred from samples?