I would like to know how to make the ticks on a colorbar show for log2.

import matplotlib.pyplot as plt
from matplotlib import ticker
x = np.arange(1000)
y = x.copy()
c = x.copy()
scatter_plot = plt.scatter(x, y, c=c, cmap='viridis', norm=matplotlib.colors.LogNorm())
formatter = ticker.LogFormatter(2)
cbar = plt.colorbar(scatter_plot, format=formatter)
plt.show()

This gives me this image:

As you can see there are some additional ticks, but it doesn't apply them properly. I want the ticks to be displayed as log2. Any help is appreciated.

CodePudding user response：

you need to use SymLogNorm and pass the parameter base=2 note you need to define a linear range where the plot is linear (to avoid having the plot go to infinity around zero), more info

Finally, note that, since you have already normalize the data to match to the proper colors using norm parameter using cbar = plt.colorbar() is enought to recover the correct colorbar, passing a without passing a formater to the colorbar.