How to add colorbars to scatterplots created like this?

Question

I create scatterplots with code that, in essence, goes like this

cmap = (matplotlib.color.LinearSegmentedColormap.
        from_list(\'blueWhiteRed\', [\'blu         


        

Answer 1

I think your best bet will be to stuff your data into a pandas dataframe, and loop through all of your markers like so:

import numpy as np    
import pandas as pd
import matplotlib.pyplot as plt

markers = ['s', 'o', '^']
records = []
for n in range(37):
    records.append([np.random.normal(), np.random.normal(), np.random.normal(), 
                    markers[np.random.randint(0, high=3)]])

records = pd.DataFrame(records, columns=['x', 'y', 'z', 'marker'])

fig, ax = plt.subplots()
for m in np.unique(records.marker):
    selector = records.marker == m
    s = ax.scatter(records[selector].x, records[selector].y, c=records[selector].z,
                   marker=m, cmap=plt.cm.coolwarm, 
                   vmin=records.z.min(), vmax=records.z.max())

cbar = plt.colorbar(mappable=s, ax=ax)
cbar.set_label('My Label')