# NumPy

New numpy English official website.

## What is NumPy?

NumPy is the basic package for scientific computing using Python. Among other things, it includes:

• A powerful N-dimensional array of objects.
• A tool that integrates C/C+ and Fortran code.
• Powerful linear algebra, Fourier transform and random number functions.

## Ndarray?

One of the most important features of NumPy is its N-dimensional array object, ndarray, which is a collection of data of the same type, starting with an index of the elements in the collection with a 0 subscript. A ndarray object is a multidimensional array used to hold elements of the same type. Each element in ndarray has an area of the same storage size in memory.

## Slice and index

The contents of a ndarray object can be accessed and modified by indexing or slicing, just like the slicing of a list in Python. Ndarray arrays can be indexed based on 0 - n subscripts. Slice objects can be cut from the original array by using the built-in slice function and setting the start, stop and step parameters.

### # As Easy as 1, 2, 3

# 1. installation package
$pip install numpy # 2. enter python's interactive interface$ python -i

# 3. Use Numpy
>>> from numpy import *
>>> eye(4)

# 4. Output result
array([[1., 0., 0., 0.],
[0., 1., 0., 0.],
[0., 0., 1., 0.],
[0., 0., 0., 1.]])


### # Contact information

• 📮Email: l@numpy.org.cn