How do I make heatmap using scatter plot data from dataframe?

Question

I have a dataframe that contains my x and y data (converted later into lists), and for each x,y I have three attributes that are percentages (all add up to 100%), so, for example, for x,y the first attribute is 0.05, the second is 0.45 and the third is 0.5.

         pc1       pc2      %_h        %_s      %_c  
0    -2.319093 -4.058990  0.718839  0.074559  0.206602  
1     1.514446 -2.324842  0.552632  0.157895  0.289474  
2    -2.431196 -1.938358  0.440313  0.071755  0.487932  
3    -2.642250 -1.001307  0.707883  0.058733  0.233385 
4    -1.486477 -2.537368  0.617834  0.151956  0.230209  
5    -1.990138 -3.457012  0.326633  0.088358  0.585008 
6    -0.844124 -3.081770  0.550000  0.113636  0.336364  
7    -2.376568 -1.471469  0.663071  0.196066  0.140863  
8    -3.139226  0.451762  0.696914  0.056173  0.246914  
    :

My aim is to make some sort of heatmap that can plot x(pc1), y(pc2) and the extent for each attribute, so darker sections would mean there is a higher density of a particular attribute. Below is the heatmap using:

plt.figure(figsize = (16,16))
plt.hist2d(pc1, pc2, bins=50, cmap=plt.cm.jet)
plt.show()

But it's based on the density of x,y points, but I want it to be based on my 3 attributes, ie red regions are for those with a high %h/%s/%c value

My research says its something to do with gridding the data and working out the frequency for each cell to get some sort of z dimensions. I've tried: Plotting a 2D heatmap with Matplotlib and: Generate a heatmap in MatPlotLib using a scatter data set (this one is based on only 2 dimensions) and have had no luck.

I would also like to plot a line graph for the density of each of the three attributes for each x.y using something like the sns.jointmap feature

EDIT What I think the approach would be is to plot a heatmap that represents the first attribute and then layer on on the other attributes after another. But I am not sure how to set the extent for the heatmap to represent the attribute and not the density counts of x,y?

EDIT This is after attempting the suggested code.

P K P K · Accepted Answer · 2019-08-07T18:33:52

Have you tried pcolormesh? Example:https://matplotlib.org/3.1.1/gallery/images_contours_and_fields/pcolormesh_levels.html

fig, ax = plt.subplots() 
data = np.array([df['%_h'],df['%_s'],df['%_c']]).reshape(3,len(df))
cax =ax.pcolormesh(df.index, np.arange(0,3), data, shading = 'gouraud', cmap = 'jet')
fig.colorbar(cax)

How do I make heatmap using scatter plot data from dataframe?

1 Answers