📜  matmul 简写 numpy - Python (1)

📅  最后修改于: 2023-12-03 15:17:35.098000             🧑  作者: Mango

Introduction to "Matmul" in Numpy - Python

Numpy is a popular library in Python that is used extensively for scientific computations with arrays, matrices, and multidimensional data. It provides a wide range of mathematical functions and operations that make it easier for programmers to work with arrays and matrices.

One such function is the matmul, which stands for matrix multiplication. In this tutorial, we will introduce you to the matmul function in Numpy and how it can be used for performing matrix multiplication operations.

What is Matmul Function?

Matmul is a function in Numpy that takes two arrays and returns their matrix multiplication. That is, it multiplies the values in the first array with those in the second array to produce a new array. The arrays must have compatible shapes, i.e., the number of columns in the first array must be equal to the number of rows in the second array.

Here is the syntax for using the matmul function in Numpy:

numpy.matmul(x1, x2, out=None)

Where:

  • x1: First input array.
  • x2: Second input array.
  • out (optional): Output array. It can be used to store the result of the matrix multiplication operation.
Example

Let's take an example to understand how the matmul function works in Numpy. Suppose we have the following two matrices:

import numpy as np

x1 = np.array([[1, 2], [3, 4]])
x2 = np.array([[5, 6], [7, 8]])

We can use the matmul function to calculate their product as follows:

result = np.matmul(x1, x2)
print(result)

Output:

[[19 22]
 [43 50]]
Conclusion

The matmul function in Numpy is a simple yet powerful function that can be used to perform matrix multiplication for two arrays. It can save a lot of time and effort for programmers who need to perform such operations frequently in their programs.