How to set number of ticks in plt.colorbar?

python matplotlib colorbar
FrankTheTank picture FrankTheTank · Feb 25, 2014 · Viewed 22.4k times · Source

When I plot a matrix with a colorbar, then the colorbar has 10 ticks. Since the colorbar has to be pretty small, the ticklabels overlap. Therefore I want to reduce the number of ticks from 10 to 5. I do not want to reduce the font size!

Is there an easy way to do this? I do not want to set the ticks manually...

Answer

Bonlenfum picture Bonlenfum · Feb 25, 2014

The MaxNLocator ticker might suit your purposes?

class matplotlib.ticker.MaxNLocator

Select no more than N intervals at nice locations

For example:

from matplotlib import ticker

# (generate plot here)
cb = plt.colorbar()
tick_locator = ticker.MaxNLocator(nbins=5)
cb.locator = tick_locator
cb.update_ticks()
plt.show()

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