plot_2d_hist set log Z

[alozar-si]

Hello, does plothist support setting log scale on Z axis for 2D hist?

[0ctagon]

Hello!

Thank you for your question.
It does support this feature through the pcolormesh_kwargs and its norm argument (see doc here). You'll need to specify the color scale using a LogNorm (doc here).

If we take the 2d_hist_simple.py example from the documentation, this is how it is implemented:

from plothist import get_dummy_data

df = get_dummy_data()

from plothist import make_2d_hist, plot_2d_hist
import matplotlib.pyplot as plt
from matplotlib.colors import LogNorm
import numpy as np

name_x = "variable_0"
name_y = "variable_1"

h = make_2d_hist([df[name_x], df[name_y]])

norm = LogNorm(vmin=1, vmax=10000) # Here we define the log scale. We could also use np.max(h.values()) to get the maximal value of h as the upper bin of the scale.

fig, ax, ax_colorbar = plot_2d_hist(
    h, colorbar_kwargs={"label": "Entries"}, pcolormesh_kwargs={"norm": norm} # Just add the norm argument to the pcolormesh_kwargs
)

ax.set_xlabel(name_x)
ax.set_ylabel(name_y)

ax.set_xlim(-10.5, 10)
ax.set_ylim(-9.3, 10)

fig.savefig("2d_hist_simple.pdf", bbox_inches="tight")