Color map to shades of blue - python

Question

I have the following (example) code:

import numpy as np
import matplotlib.pyplot as plt
import matplotlib as mpl


n_lines = 5
x = np.linspace(0, 10, 100)
y = np.sin(x[:, None] + np.pi * np.linspace(0, 1, n_lines))
c = np.arange(1, n_lines + 1)

norm = mpl.colors.Normalize(vmin=c.min(), vmax=c.max())
cmap = mpl.cm.ScalarMappable(norm=norm, cmap=mpl.cm.jet)
cmap.set_array([])

fig, ax = plt.subplots(dpi=100)
for i, yi in enumerate(y.T):
    ax.plot(x, yi, c=cmap.to_rgba(i + 1))
fig.colorbar(cmap, ticks=c)
plt.show();

I would like to find a substirute for cmap.to_rgba that makes the colour of each line come out as a differnet shade of blue.
Basically I want to keep the same layout as the result of this code, but using the colour map Blues .

How can I do it?

Answer 1

You need to change your colormap that you are using from jet to Blues .

import numpy as np
import matplotlib.pyplot as plt
import matplotlib as mpl


n_lines = 5
x = np.linspace(0, 10, 100)
y = np.sin(x[:, None] + np.pi * np.linspace(0, 1, n_lines))
c = np.arange(1, n_lines + 1)

norm = mpl.colors.Normalize(vmin=c.min(), vmax=c.max())
cmap = mpl.cm.ScalarMappable(norm=norm, cmap=mpl.cm.Blues)
cmap.set_array([])

fig, ax = plt.subplots(dpi=100)
for i, yi in enumerate(y.T):
   ax.plot(x, yi, c=cmap.to_rgba(i + 1))
fig.colorbar(cmap, ticks=c)
plt.show()

This produces: