JIYIK CN >

This tutorial shows how to use matplotlib.pyplot.imshow()the and matplotlib.pyplot.pcolormesh()methods in Python to generate colorplots of 2D arrays.

In Matplotlib, we use matplotlib.pyplot.imshow()the method to plot 2D arrays.

matplotlib.pyplot.imshow()The method takes a 2D array as input and renders the given array as a raster image.

matplotlib.pyplot.imshow()Syntax

matplotlib.pyplot.imshow(X,
                         cmap=None,
                         norm=None,
                         aspect=None,
                         interpolation=None,
                         alpha=None,
                         vmin=None,
                         vmax=None,
                         origin=None,
                         extent=None, *,
                         filternorm=True,
                         filterrad=4.0,
                         resample=None,
                         url=None,
                         data=None,
                         **kwargs)

matplotlib.pyplot.imshow()Example

import numpy as np
import matplotlib.pyplot as plt

X = np.random.randint(256, size=(10, 10))

fig = plt.figure(figsize=(8, 6))
plt.imshow(X)
plt.title("Plot 2D array")
plt.show()

It plots a 2D array of numpy.random.randint()size created using 10*10. By default, the values ​​are viridismapped using a colormap.

We can change the colormap by imshow()setting cmapthe parameter in the method.

import numpy as np
import matplotlib.pyplot as plt

X = np.random.randint(256, size=(10, 10))

fig = plt.figure(figsize=(8, 6))
plt.imshow(X, cmap="inferno")
plt.title("Plot 2D array")
plt.colorbar()
plt.show()

It shows infernoa 2D array plot with a colormap. We can also see a colorbar on the right side of the plot, which tells us which values ​​in the array are mapped to which colors.

In Matplotlib, we use matplotlib.pyplot.pcolormesh()the method to plot 2D arrays.

matplotlib.pyplot.pcolormesh()The function creates a pseudocolor plot in Matplotlib. It matplotlib.pyplot.pcolor()is similar to the function.

import numpy as np
import matplotlib.pyplot as plt

X = np.random.randint(256, size=(10, 10))

fig = plt.figure(figsize=(8, 6))
plt.pcolormesh(X, cmap="plasma")
plt.title("Plot 2D array")
plt.colorbar()
plt.show()

It plots a 2D array of numpy.random.randint()size created using 10*10and plasmaa colormap. The colorbar on the right represents the colors assigned to different value ranges.