Wrong spacing when adding a risk table to a subplot

[Godrebh]

When plotting Kaplan Meier curves within subplots and adding the risk table, the spacing between plot and table is off and they may even overlap. This is because the y-position of the table is calculated by using the figure height, when acutally the subplot height would be necessary here.

In the function liflines.plotting.add_at_risk_counts() , I replaced the line: ax2_ypos = -0.15 * 6.0 / fig.get_figheight() with

ax_height = (ax.get_position().y1 - ax.get_position().y0) * fig.get_figheight() # axis height
ax2_ypos = -0.1 * 6.0 / ax_height

and this looks much better.

[CamDavidsonPilon]

oh nice! Let me try this locally, and implement this fix for the next release. Thanks!

[CamDavidsonPilon]

Hm, I haven't been able to reproduce the bug locally. Can you provide a small code snippet of what caused the initial problem?

[Godrebh]

Sure, here you go:

import lifelines
import matplotlib as mpl
import matplotlib.pyplot as plt
from lifelines.datasets import load_waltons
waltons = load_waltons()
ix = waltons['group'] == 'control'

img_no = 3

height = 4 * img_no
half_inch = 0.5 / height  # in percent height
_fig = plt.figure(figsize=(6, height), dpi=300)
gs = mpl.gridspec.GridSpec(img_no, 1)
plt.subplots_adjust(left=0.08, right=0.98, bottom=half_inch, top=1-half_inch)

for i in range(img_no):
    ax = plt.subplot(gs[i, 0])
    kmf_control = lifelines.KaplanMeierFitter()
    ax = kmf_control.fit(waltons.loc[ix]['T'], waltons.loc[ix]['E'], label='control').plot(ax=ax)
    kmf_exp = lifelines.KaplanMeierFitter()
    ax = kmf_exp.fit(waltons.loc[~ix]['T'], waltons.loc[~ix]['E'], label='exp').plot(ax=ax)
    ax = lifelines.plotting.add_at_risk_counts(kmf_exp, kmf_control, ax=ax)

plt.subplots_adjust(hspace=0.6)
plt.savefig('kaplan_meier.png')
plt.close()

With img_no = 1, everything looks fine, but the more images are added, the worse the overlap will get. The height of each subplot image here is 4 inch, but with the three subplots the figure height is 12 and this is used to calculate the y position of the table. What I propose does calculate the height of the axis, which is not exactly 4, but a bit less. I also changed the -0.15 to -0.1, because it looked a bit better.

[CamDavidsonPilon]

Fixed in v0.24.5