Minor ticks with only major tick labels are shown

Question

I would like to have minor ticks on a axis but show only major tick labels. For instance, minor ticks are [19, 20, 21, ... 40, 41] and major tick labels are [20, 25, 30, 35, 40]

Answer 1

I don't really understand why is it difficult to use MultipleLocator in your example.

By adding these lines in your code

from matplotlib.ticker import MultipleLocator, FormatStrFormatter

majorLocator   = MultipleLocator(5)
majorFormatter = FormatStrFormatter('%d')
minorLocator   = MultipleLocator(1)

ax.xaxis.set_major_locator(majorLocator)
ax.xaxis.set_major_formatter(majorFormatter)
ax.xaxis.set_minor_locator(minorLocator)

You'll get this image, which I understood it is what you want (isn't it?):

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In case you don't want the ticks to show below your range of data, define your ticks manually using the FixedLocator:

from matplotlib.ticker import FixedLocator

majorLocator   = FixedLocator(np.linspace(20,40,5))
minorLocator   = FixedLocator(np.linspace(19,41,23))

And you'll get this image: