matplotlib.pyplot.nipy_spectral() in Python

Matplotlib is a library in Python and it is numerical – mathematical extension for NumPy library. Pyplot is a state-based interface to a Matplotlib module which provides a MATLAB-like interface.

matplotlib.pyplot.nipy_spectral() Function:

The nipy_spectral() function in pyplot module of matplotlib library is used to set the colormap to “nipy_spectral”.

Syntax:

matplotlib.pyplot.nipy_spectral()

Parameters: This method does not accepts any parameters.

Return value: This method does not returns any value.

Below examples illustrate the matplotlib.pyplot.nipy_spectral() function in matplotlib.pyplot:

Example #1:

# Implementation of matplotlib function
import matplotlib.pyplot as plt
import matplotlib.tri as tri
import numpy as np

ang = 40
rad = 10
radm = 0.35
radii = np.linspace(radm, 0.95, rad)

angles = np.linspace(0, 4 * np.pi, ang)
angles = np.repeat(angles[..., np.newaxis], rad, axis = 1)
angles[:, 1::2] += np.pi / ang

x = (radii * np.cos(angles)).flatten()
y = (radii * np.sin(angles)).flatten()
z = (np.sin(4 * radii) * np.cos(4 * angles)).flatten()

triang = tri.Triangulation(x, y)
triang.set_mask(np.hypot(x[triang.triangles].mean(axis = 1),
                         y[triang.triangles].mean(axis = 1))
                < radm)

tpc = plt.tripcolor(triang, z, shading ='flat')
plt.nipy_spectral()
plt.title('matplotlib.pyplot.nipy_spectral() function Example', fontweight ="bold")
plt.show()

Output:

Example #2:

# Implementation of matplotlib function
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.colors import LogNorm

dx, dy = 0.015, 0.05
x = np.arange(-3.0, 3.0, dx)
y = np.arange(-3.0, 3.0, dy)
X, Y = np.meshgrid(x, y)

extent = np.min(x), np.max(x), np.min(y), np.max(y)


Z1 = np.add.outer(range(6), range(6)) % 2
plt.imshow(Z1, cmap ="binary_r", interpolation ='nearest',
                 extent = extent, alpha = 1)

def geeks(x, y):
    return (1 - x / 2 + x**5 + y**6) * np.exp(-(x**2 + y**2))

Z2 = geeks(X, Y)

plt.imshow(Z2, alpha = 0.7, interpolation ='bilinear',
                 extent = extent)
plt.nipy_spectral()
plt.title('matplotlib.pyplot.nipy_spectral() function Example', fontweight ="bold")
plt.show()

Output: