np.asmatrix

As an AI language model, I do not have access to the implementation details of specific programming languages. However, I can provide a general description of the `np.asmatrix` function from the context of Python and NumPy.

In NumPy, `np.asmatrix` is a function that converts the input array or matrix-like object into a matrix object. It returns a new matrix object that shares the same data and memory as the input object, but with a different representation. Unlike the array class, matrix objects in NumPy are always two-dimensional, and some matrix-specific operations are defined on them.

Here is an example of how to use `np.asmatrix` in Python:

import numpy as np

# create an array
a = np.array([[1, 2], [3, 4]])

# convert the array to a matrix object
m = np.asmatrix(a)

# print the matrix
print(m)

This will output:

[[1 2]
 [3 4]]

Note that `m` is now a matrix object, which can be used for matrix multiplication, inversion, and other operations that are not defined for arrays.