Multivariate views

In this notebook, we show a few examples of how to have plots with graphs of different types in a figure, like having a scatter plot with marginal distributions or even a multivariate plot with pair relationships of all properties in a table.

import pandas as pd
import seaborn as sns

Let’s load the same dataframe.

df = pd.read_csv("data/BBBC007_analysis.csv")
df

	area	intensity_mean	major_axis_length	minor_axis_length	aspect_ratio	file_name
0	139	96.546763	17.504104	10.292770	1.700621	20P1_POS0010_D_1UL
1	360	86.613889	35.746808	14.983124	2.385805	20P1_POS0010_D_1UL
2	43	91.488372	12.967884	4.351573	2.980045	20P1_POS0010_D_1UL
3	140	73.742857	18.940508	10.314404	1.836316	20P1_POS0010_D_1UL
4	144	89.375000	13.639308	13.458532	1.013432	20P1_POS0010_D_1UL
...	...	...	...	...	...	...
106	305	88.252459	20.226532	19.244210	1.051045	20P1_POS0007_D_1UL
107	593	89.905565	36.508370	21.365394	1.708762	20P1_POS0007_D_1UL
108	289	106.851211	20.427809	18.221452	1.121086	20P1_POS0007_D_1UL
109	277	100.664260	20.307965	17.432920	1.164920	20P1_POS0007_D_1UL
110	46	70.869565	11.648895	5.298003	2.198733	20P1_POS0007_D_1UL

111 rows × 6 columns

Scatter plot

A very basic visualization of such datasets is the scatter plot.

sns.scatterplot(data=df, x="aspect_ratio", y="area");

Plotting joint and marginal distributions

The jointplot gives us more insights into the data, and has the same parameters though.

sns.jointplot(data=df, x="aspect_ratio", y="area");

As expected, it is possible to separate groups by passing a categorical property to the hue argument. This has an effect on the marginal distribution, turning them from histogram to kde plots.

sns.jointplot(data=df,
              x="aspect_ratio",
              y="area",
              hue='file_name');

Plotting many distributions at once

The above examples displayed a plot with relationship between two variables. This can be further expanded with the pairplot function which displays the relationship between all variables in a table. The result is a matrix of scatter plots with an univariate distribution of each variable on the diagonal.

sns.pairplot(data=df);

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Exercise

You may have noticed that the pairplot is redundant in some plots because the upper diagonal displays the same relationships rotated.

Redraw the pairplot to display only the lower diagonal of the plots.

Hint: explore the properties of the pairplot.