CODE EXAMPLE FOR PYTHON

change font size pandas scatter_matrix

scatter_matrix = pd.scatter_matrix(
    data,
    figsize  = [15, 15],
    marker   = ".",
    s        = 0.2,
    diagonal = "kde"
)

for ax in scatter_matrix.ravel():
    ax.set_xlabel(ax.get_xlabel(), fontsize = 20, rotation = 90)
    ax.set_ylabel(ax.get_ylabel(), fontsize = 20, rotation = 0)