# Matplotlib.pyplot.gray() in Python

• Last Updated : 21 Apr, 2020

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.gray() Function

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

Syntax:

```matplotlib.pyplot.gray()
```

Below examples illustrate the matplotlib.pyplot.gray() 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``, ``3` `*` `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.colorbar(tpc)``plt.gray()``plt.title('matplotlib.pyplot.gray() function\``Example\n\n', 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(``-``4.0``, ``4.0``, dx)``y ``=` `np.arange(``-``4.0``, ``4.0``, 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``(``8``), ``range``(``8``)) ``%` `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.gray()``plt.title(``'matplotlib.pyplot.gray() function Example\n\n'``,``          ``fontweight ``=``"bold"``)`` ` `plt.show()`

Output:

My Personal Notes arrow_drop_up