xedges = np.linspace(-10, 10, 100)
yedges = np.linspace(-10, 10, 100)
zedges = np.linspace(-10, 10, 10)
hist, edges = np.histogramdd((delta, vf, dS), (xedges, yedges, zedges))
xidx, yidx, zidx = np.where(hist > 0)
plt.scatter(xedges[xidx], yedges[yidx], c=zedges[zidx], alpha=0.7, cmap=cm.
    Paired)
plt.show()
Scatter plot with a huge amount of data