#!/usr/bin/env python
# coding: utf-8

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import yt


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ds = yt.load('IsolatedGalaxy/galaxy0030/galaxy0030')
slc = yt.SlicePlot(ds, 'x', ('gas', 'density'))
slc


# `PlotWindow` plots are containers for plots, keyed to field names.  Below, we get a copy of the plot for the `Density` field.

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plot = slc.plots[('gas', 'density')]


# The plot has a few attributes that point to underlying `matplotlib` plot primitives.  For example, the `colorbar` object corresponds to the `cb` attribute of the plot.

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colorbar = plot.cb


# Next, we call `_setup_plots()` to ensure the plot is properly initialized. Without this, the custom tickmarks we are adding will be ignored.

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slc._setup_plots()


# To set custom tickmarks, simply call the `matplotlib` [`set_ticks`](https://matplotlib.org/stable/api/colorbar_api.html#matplotlib.colorbar.ColorbarBase.set_ticks) and [`set_ticklabels`](https://matplotlib.org/stable/api/colorbar_api.html#matplotlib.colorbar.ColorbarBase.set_ticklabels) functions.

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colorbar.set_ticks([1e-28])
colorbar.set_ticklabels(['$10^{-28}$'])
slc