# numpy.asmatrix() – The NumPy asmatrix Python Function

## Introduction to NumPy asmatrix

Guide to NumPy asmatrix – Consider the data as a matrix. If the input is already a matrix or a ndarray, unlike a matrix, asmatrix does not produce a copy. Matrix(data, copy=False) is the same as matrix(data, copy=False).

Syntax:

`numpy.asmatrix(data, dtype=None)`

Parameters:

• data : array-like input data
• dtype : Data type of returned array

Return: Interprets the input as a matrix

## Code Example of NumPy asmatrix

Example 01:

``````# welcome to softhunt.net
# Python Programming illustrating
# numpy.asmatrix

import numpy as np

# array-like input
b = np.matrix([[1, 2, 3], [4, 5]])
print("Via array-like input : \n", b, "\n")

c = np.asmatrix(b)
b[0, 1] = 15
print("c matrix : \n", c)``````

Output:

```Via array-like input :
[[list([1, 2, 3]) list([4, 5])]]

c matrix :
[[list([1, 2, 3]) 15]]```

Note: These programs will not run in online IDEs. Please test them on your systems to see how they operate.

## FAQs

### What is NumPy asmatrix?

asmatrix() is a function that returns a matrix. The asmatrix() function is used to transform an input into a matrix. If the input is already a matrix or a ndarray, unlike a matrix, asmatrix does not produce a copy. Matrix(data, copy=False) is the same as matrix(data, copy=False).

### How do you multiply matrices with Numpy?

If the number of columns in one matrix equals the number of rows in the second matrix, the two matrices can be multiplied.

If matrix 1 has dimensions of a * N and matrix 2 has dimensions of N * b, the final matrix will have dimensions of a * b.

The following code shows an example of multiplying matrices in NumPy:

``````# welcome to softhunt.net
import numpy as np
# two dimensional arrays
m1 = np.array([[1,5,3],[2,4,2]])
m2 = np.array([[6,7],[2,7],[3,1]])
m3 = np.dot(m1,m2)
print('Two dimensional array:\n', m3)

# three dimensional arrays
m1 = ([1, 3, 5],[6 ,7, 2],[6, 23, 2])
m2 = ([3, 4, 6],[8, 34, 6],[6, 5, 7])
m3 = np.dot(m1,m2)
print('Three dimensional array:\n', m3)
``````

Output:

```Two dimensional array:
[[25 45]
[26 44]]
Three dimensional array:
[[ 57 131  59]
[ 86 272  92]
[214 816 188]]```

### How do you add a NumPy to a matrix?

In NumPy, use the append() function to add a row to a matrix. The NumPy module’s append() function may be used to add elements to the end of an array. We may use this method to add rows to a matrix by setting the axis to 0.

## Conclusion

That’s all for this article, if you have any confusion contact us through our website or email us at [email protected] or by using LinkedIn. And make sure you check out our NumPy tutorials.

Suggested Articles:

1. numpy.asanyarray() – The NumPy asanyarray Python Function