CODEWITHSUNDEEP
pythonpython-3.xmatplotlibseaborn
Arkistarvh Kltzuonstev
Arkistarvh Kltzuonstev

Reputation: 6935

How to plot only the lower triangle of a seaborn heatmap?

I've a list of lists all_genres where each sub-lists contain genres for a particular tv-show and each different sub-list refers to different tv-shows. I want to plot a seaborn heatmap but with only the lower traiangle part. Here is what I've tried so far :

import numpy as np
import matplotlib.pyplot as plt
import seaborn as sns
sns.set(rc={'figure.figsize':(16,9)})

all_genres = [['Drama', 'History'], ['Documentary'], ['Action', 'Drama', 'History'], ['Documentary'], ['Crime', 'Drama', 'Thriller'], ['Action', 'Adventure', 'Drama'], ['Crime', 'Drama', 'Thriller'], ['Documentary'], ['Documentary'], ['Documentary'], ['Animation', 'Adventure', 'Comedy'], ['Crime', 'Drama'], ['Documentary', 'History', 'War'], ['Animation', 'Action', 'Adventure'], ['Documentary'], ['Documentary', 'Music'], ['Crime', 'Drama', 'Mystery'], ['Documentary', 'History', 'War'], ['Fantasy', 'Horror', 'Mystery'], ['Documentary'], ['Drama'], ['Animation', 'Action', 'Adventure'], ['Adventure', 'Drama', 'Sci-Fi'], ['Documentary', 'History', 'War'], ['Biography', 'Drama', 'History'], ['Crime', 'Drama', 'Mystery'], ['Crime', 'Drama', 'Thriller'], ['Animation', 'Action', 'Adventure'], ['Animation', 'Crime', 'Drama'], ['Comedy', 'News', 'Talk-Show'], ['Documentary'], ['Animation', 'Action', 'Adventure'], ['Drama', 'Sci-Fi', 'Thriller'], ['Documentary'], ['Animation', 'Action', 'Adventure'], ['Comedy'], ['Comedy', 'Romance'], ['Drama', 'Romance'], ['Documentary'], ['Comedy'], ['Drama', 'Thriller', 'War'], ['Comedy'], ['Documentary', 'History', 'War'], ['Drama', 'Fantasy', 'Horror'], ['Animation', 'Adventure', 'Comedy'], ['Crime', 'Drama', 'Fantasy'], ['Comedy'], ['Animation', 'Adventure', 'Drama'], ['Comedy', 'Drama'], ['Comedy', 'Drama'], ['Biography', 'Crime', 'Drama'], ['Comedy', 'Drama'], ['Biography', 'Drama', 'History'], ['Comedy'], ['Drama'], ['Crime', 'Drama'], ['Comedy', 'War'], ['Drama', 'Mystery', 'Sci-Fi'], ['Action', 'Comedy', 'Drama'], ['Action', 'Drama', 'History'], ['Animation', 'Action', 'Adventure'], ['Comedy'], ['Crime', 'Drama', 'Thriller'], ['Animation', 'Comedy'], ['Crime', 'Drama', 'Mystery'], ['Crime', 'Thriller'], ['Animation', 'Action', 'Adventure'], ['Comedy'], ['Animation', 'Comedy'], ['Drama'], ['Drama', 'Mystery'], ['Comedy', 'Music'], ['Documentary', 'Comedy'], ['Comedy', 'Drama'], ['Animation', 'Action', 'Adventure'], ['Crime', 'Drama', 'History'], ['Animation', 'Action', 'Adventure'], ['Crime', 'Drama', 'Mystery'], ['Animation', 'Comedy', 'Drama'], ['Adventure', 'Drama', 'Western'], ['Documentary', 'Talk-Show'], ['Documentary', 'Crime'], ['Action', 'Adventure', 'Drama'], ['Drama', 'Horror', 'Mystery'], ['Crime', 'Drama'], ['Comedy'], ['Comedy', 'Drama'], ['Crime', 'Drama', 'Mystery'], ['Drama', 'History'], ['Crime', 'Drama', 'Mystery'], ['Crime', 'Drama', 'Mystery'], ['Crime', 'Drama', 'Thriller'], ['Comedy', 'Talk-Show'], ['Drama', 'Romance'], ['Animation', 'Crime', 'Drama'], ['Crime', 'Drama', 'Mystery'], ['Crime', 'Drama', 'Mystery'], ['Comedy'], ['Animation', 'Action', 'Adventure'], ['Animation', 'Action', 'Comedy'], ['Action', 'Drama', 'History'], ['Crime', 'Mystery', 'Thriller'], ['Comedy', 'Talk-Show'], ['Action', 'Adventure', 'Mystery'], ['Animation', 'Short', 'Comedy'], ['Action', 'Crime', 'Drama'], ['Comedy'], ['Comedy', 'Drama', 'Romance'], ['Animation', 'Action', 'Adventure'], ['Documentary', 'Crime'], ['Comedy', 'Drama', 'Music'], ['Comedy'], ['Drama', 'Romance'], ['Action', 'Crime', 'Drama'], ['Animation', 'Action', 'Adventure'], ['Drama', 'History', 'War'], ['Crime', 'Drama', 'Thriller'], ['Drama'], ['Action', 'Comedy'], ['Animation', 'Comedy'], ['Documentary', 'Adventure'], ['Documentary'], ['Comedy', 'Drama'], ['Animation', 'Action', 'Adventure'], ['Comedy', 'Game-Show'], ['Drama', 'Sport'], ['Adventure', 'Drama', 'Family'], ['Comedy'], ['Comedy'], ['Crime', 'Drama', 'Mystery'], ['Comedy'], ['Adventure', 'Comedy', 'Drama'], ['Family', 'Fantasy', 'Music'], ['Comedy', 'Drama'], ['Drama', 'Romance'], ['Animation', 'Action', 'Adventure'], ['Drama'], ['Action', 'Crime', 'Drama'], ['Comedy', 'Music', 'Musical'], ['Comedy'], ['Animation', 'Action', 'Drama'], ['Documentary'], ['Crime', 'Drama', 'Mystery'], ['Drama', 'War'], ['Animation', 'Action', 'Adventure'], ['Crime', 'Drama', 'Mystery'], ['Comedy', 'Drama'], ['Documentary', 'Biography', 'Crime'], ['Crime', 'Drama', 'History'], ['Comedy'], ['Animation', 'Action', 'Adventure'], ['Animation', 'Action', 'Adventure'], ['Biography', 'Drama', 'History'], ['Comedy', 'Talk-Show'], ['Comedy', 'Sci-Fi'], ['Comedy'], ['Crime', 'Drama'], ['Comedy', 'Crime', 'Drama'], ['Comedy', 'Drama'], ['Comedy', 'Romance'], ['Animation', 'Action', 'Adventure'], ['Crime', 'Drama', 'Mystery'], ['Action', 'Adventure', 'Crime'], ['Animation', 'Action', 'Adventure'], ['Comedy'], ['Animation', 'Action', 'Adventure'], ['Crime', 'Drama', 'Thriller'], ['Comedy', 'Family'], ['Documentary', 'History', 'War'], ['Biography', 'Drama'], ['Comedy'], ['Comedy', 'Musical', 'Sci-Fi'], ['Animation', 'Comedy', 'Drama'], ['Documentary', 'Sport'], ['Comedy', 'Game-Show'], ['Action', 'Adventure', 'Drama'], ['Comedy', 'Reality-TV'], ['Animation', 'Action', 'Adventure'], ['Drama', 'Romance'], ['Crime', 'Drama', 'Horror'], ['Comedy'], ['Comedy', 'Drama', 'Family'], ['Crime', 'Drama', 'Thriller'], ['Crime', 'Drama', 'Mystery'], ['Animation', 'Drama', 'Fantasy'], ['Action', 'Adventure', 'Biography'], ['Comedy', 'Drama'], ['Drama', 'Fantasy', 'Romance'], ['Action', 'Crime', 'Mystery'], ['Crime', 'Drama', 'Thriller'], ['Crime', 'Drama', 'Mystery'], ['Crime', 'Drama', 'Thriller'], ['Drama', 'Mystery', 'Sci-Fi'], ['Drama', 'Sci-Fi', 'Thriller'], ['Animation', 'Comedy', 'Sci-Fi'], ['Crime', 'Drama', 'Mystery'], ['Drama', 'Thriller'], ['Comedy'], ['Drama'], ['Comedy'], ['Animation', 'Action', 'Crime'], ['Biography', 'Crime', 'Drama'], ['Biography', 'Drama', 'History'], ['Comedy'], ['Action', 'Adventure', 'Biography'], ['Action', 'Comedy', 'Fantasy'], ['Crime', 'Drama'], ['Crime', 'Drama'], ['Crime', 'Drama'], ['Comedy', 'Drama', 'Romance'], ['Animation', 'Action', 'Adventure'], ['Animation', 'Action', 'Family'], ['Drama'], ['Animation', 'Comedy', 'Sci-Fi'], ['Action', 'Drama', 'History'], ['Crime', 'Drama', 'Mystery'], ['Crime', 'Drama'], ['Comedy', 'News', 'Talk-Show'], ['Animation', 'Action', 'Adventure'], ['Animation', 'Action', 'Adventure'], ['Drama', 'Mystery', 'Thriller'], ['Comedy', 'News', 'Talk-Show'], ['Comedy', 'Fantasy', 'Horror'], ['Drama', 'Fantasy', 'Mystery'], ['Adventure', 'Fantasy'], ['Animation', 'Action', 'Adventure'], ['Comedy', 'Crime'], ['Crime', 'Drama'], ['Comedy', 'Drama'], ['Drama', 'Mystery', 'Sci-Fi'], ['Comedy', 'Drama'], ['Comedy', 'Talk-Show'], ['Drama'], ['Animation', 'Family', 'Comedy'], ['Comedy', 'Horror'], ['Comedy', 'Drama'], ['Drama'], ['Documentary', 'Short'], ['Crime', 'Drama', 'Mystery'], ['Comedy', 'Romance'], ['Comedy', 'Family', 'Music'], ['Drama', 'Mystery', 'Sci-Fi'], ['Comedy', 'Crime']]
unique_genres = sorted({i for j in all_genres for i in j})
genre_matrix = []
for i in unique_genres:
    temp = []
    for j in unique_genres:
        s = sum(1  if i in m and j in m and i!=j else 0 for m in all_genres)
        temp.append(s)
    genre_matrix.append(temp)
genre_matrix = np.array(genre_matrix)

ax = sns.heatmap(genre_matrix, xticklabels=unique_genres, yticklabels=unique_genres, annot=True, linewidths=.42, cbar=True, cbar_kws={'label': 'Colorbar'})
#plt.savefig('seaborn_cross_fold_plot.png', bbox_inches="tight", pad_inches=0)
plt.show()

The resultant picture is this : seaborn plot

I want to get only the lower or bottom part of this heatmap as the the left bottom part and upper right part would be same i.e. they are just reflection wrt the diagonal line. The resultant picture I want to get is something like this :

result

How to do this in seaborn or in matplotlib?

Upvotes: 24

Views: 42404

Answers (3)

Hamzah Al-Qadasi
Hamzah Al-Qadasi

Reputation: 9786

You can re-use this example:

import seaborn as sns
import matplotlib.pyplot as plt

df = sns.load_dataset('car_crashes')
corr =  df.corr()

# Create a mask
mask = np.triu(np.ones_like(corr, dtype=bool))

# Create a custom divergin palette
cmap = sns.diverging_palette(100, 7, s=75, l=40,
                            n=5, center="light", as_cmap=True)

plt.figure(figsize=(10, 6))
sns.heatmap(corr, mask=mask, center=0, annot=True,
            fmt='.2f', square=True, cmap=cmap)

plt.show();

enter image description here

If you want to show the main diagonal, you can add this:

np.fill_diagonal(mask, False)

Credits for here

Upvotes: 8

teddcp
teddcp

Reputation: 1624

Bit a late to the Party!... Another way

corr= df_new.corr()

# Getting the Upper Triangle of the co-relation matrix
matrix = np.triu(corr)

# using the upper triangle matrix as mask 
sns.heatmap(corr, annot=True, mask=matrix)

Upvotes: 47

son520804
son520804

Reputation: 483

You can look at https://seaborn.pydata.org/examples/many_pairwise_correlations.html and find out that 

mask = np.zeros_like(corr, dtype=np.bool)
mask[np.triu_indices_from(mask)] = True

will be the code for masking the upper triangle part of the matrix.And then you would change the code of sns.heatmap to the following (as the website suggests):

sns.heatmap(corr, mask=mask, cmap=cmap, vmax=.3, center=0,
            square=True, linewidths=.5, cbar_kws={"shrink": .5})

You can customize other attributes if you want after that.

Upvotes: 7

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