Follow

Keep Up to Date with the Most Important News

By pressing the Subscribe button, you confirm that you have read and are agreeing to our Privacy Policy and Terms of Use
Contact

How does one insert statistical annotations (e.g. p-values) into a seaboarn figure-level plot (e.g. catplot)?

Goal: Given a seaborn catplot (kind="bar") with multiple rows, grouped bars, and a mapped stripplot, how do I add statistical annotations (p-values).

The following code from @Trenton McKinney generates my figure without statistical annotation. I would like to insert statistical annotation into this figure:

import seaborn as sns

tips = sns.load_dataset("tips")

g = sns.catplot(x="sex", y="total_bill", hue="smoker", row="time", data=tips, kind="bar", ci = "sd", 
    edgecolor="black", errcolor="black", errwidth=1.5, capsize = 0.1, height=4, aspect=.7,alpha=0.5)

g.map(sns.stripplot, 'sex', 'total_bill', 'smoker', hue_order=['Yes', 'No'], order=['Male', 'Female'],
  palette=sns.color_palette(), dodge=True, alpha=0.6, ec='k', linewidth=1)

Catplot without statistical annotation

MEDevel.com: Open-source for Healthcare and Education

Collecting and validating open-source software for healthcare, education, enterprise, development, medical imaging, medical records, and digital pathology.

Visit Medevel


What I tried: I tried to use statannotations.Annotator.Annotator.plot_and_annotate_facets(). However, I was not able to get it working properly.

I also tried to use statannotations.Annotator.Annotator.new_plot(). However, this just worked for barplots but not for catplots. This is the corresponding code based on @r-beginners:

import seaborn as sns
from statannotations.Annotator import Annotator
%matplotlib inline
import matplotlib.pyplot as plt

df = sns.load_dataset("tips")

x="sex"
y="total_bill"
hue="smoker"
hue_order=['Yes', 'No']

pairs = [
    (("Male", "Yes"), ("Male", "No")),
    (("Female", "Yes"), ("Female", "No"))]

ax = sns.barplot(data=df, x=x, y=y, hue=hue, hue_order=hue_order, seed=2021, ci="sd", 
    edgecolor="black", errcolor="black", errwidth=1.5, capsize = 0.1, alpha=0.5)

sns.stripplot(x=x, y=y, hue=hue, data=df, dodge=True, alpha=0.6, ax=ax)

annot = Annotator(None, pairs)

annot.new_plot(ax, pairs, plot='barplot',
           data=df, x=x, y=y, hue=hue, hue_order=hue_order, seed=2021)
annot.configure(test='Mann-Whitney', text_format='simple', loc='inside', verbose=2)
annot.apply_test().annotate()

plt.legend(loc='upper left', bbox_to_anchor=(1.03, 1), title=hue)

Statistical annotation for a barplot

Question: Does anyone know how to insert statistical annotation into a figure-level plot, preferably a catplot (kind="bar")?

>Solution :

I think you can just iterate over the axes in the FacetGrid and apply the Annotator element wise.

Here is a short example with your provided code:

import seaborn as sns
from statannotations.Annotator import Annotator
%matplotlib inline


tips = sns.load_dataset("tips")

args = dict(x="sex", y="total_bill", data=tips, hue="smoker", hue_order=["Yes","No"], order=['Male', 'Female'])

g = sns.catplot(edgecolor="black", errcolor="black", errwidth=1.5, capsize = 0.1, height=4, aspect=.7,alpha=0.5, kind="bar", ci = "sd", row="time", **args)
g.map(sns.stripplot, args["x"], args["y"], args["hue"], hue_order=args["hue_order"], order=args["order"], palette=sns.color_palette(), dodge=True, alpha=0.6, ec='k', linewidth=1)

pairs = [
    (("Male", "Yes"), ("Male", "No")),
    (("Female", "Yes"), ("Female", "No"))
]

for ax_n in g.axes:
    for ax in ax_n:
        annot = Annotator(ax, pairs, **args)
        annot.configure(test='Mann-Whitney', text_format='simple', loc='inside', verbose=2)
        annot.apply_test().annotate()

This produces the following plot:
Plot with annotations

Add a comment

Leave a Reply

Keep Up to Date with the Most Important News

By pressing the Subscribe button, you confirm that you have read and are agreeing to our Privacy Policy and Terms of Use

Discover more from Dev solutions

Subscribe now to keep reading and get access to the full archive.

Continue reading