Axes-level customization

You may find the default style in Marsilea does not fit your taste. You can customize the plot by accessing the axes directly.

Retrieve main axes

No axes or figure is created or render until you call the render() method.

After you render the visualization, you can access the main axes by get_main_ax().

The example below shows how to add a border to your heatmap:

>>> import marsilea as ma
>>> from matplotlib.patches import Rectangle
>>> data = np.random.rand(20, 20)
>>> h = ma.Heatmap(data, linewidth=1)
>>> h.render()
>>> hax = h.get_main_ax()
>>> border = Rectangle((0, 0), 1, 1, fill=False, ec=".1", lw=5, transform=hax.transAxes)
>>> hax.add_artist(border)

When working with split heatmaps, you’ll receive multiple axes in return, ordered from the upper left to the lower right.

>>> h = ma.Heatmap(data, cmap="binary", linewidth=1)
>>> h.hsplit(cut=[5])
>>> h.vsplit(cut=[5])
>>> h.render()
>>> # Get the ax after render()
>>> hax = h.get_main_ax()
>>> print(hax)
    [<AxesSubplot: > <AxesSubplot: > <AxesSubplot: > <AxesSubplot: >]
>>> colors = ["#9a60b4", "#73c0de", "#3ba272", "#fc8452"]
>>> # purple, blue, green, orange
>>> for ax, c in zip(hax, colors):
...     border = Rectangle((0, 0), 1, 1, fill=False, ec=c, lw=5, transform=ax.transAxes)
...     ax.add_artist(border)

Retrieve side axes

To retrieve side axes, you must name the plot that you wish to customize first. Once you assign the name, you can use get_ax() to retrieve the named axes.

>>> h = ma.Heatmap(data, linewidth=1)
>>> h.hsplit(cut=[5])
>>> bar = ma.plotter.Numbers(np.arange(20))
>>> h.add_right(bar, name="My Bar")
>>> h.render()
>>> # Get the ax after render()
>>> bar_axes = h.get_ax("My Bar")
>>> colors = ["#9a60b4", "#73c0de"]
>>> # purple, blue
>>> for ax, c in zip(bar_axes, colors):
...     bg = Rectangle((0, 0), 1, 1, fc=c, zorder=-1, transform=ax.transAxes)
...     ax.add_artist(bg)