Book Image

Learning NumPy Array

By : Ivan Idris
Book Image

Learning NumPy Array

By: Ivan Idris

Overview of this book

Table of Contents (14 chapters)
Learning NumPy Array
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Selecting array elements


From time to time, we will want to select a particular element of an array. We will take a look at how to do this, but first, let's create a 2 x 2 matrix again (see the elementselection.py file in the Chapter02 folder of this book's code bundle):

In: a = array([[1,2],[3,4]])
In: a
Out:
array([[1, 2],       [3, 4]])

The matrix was created this time by passing a list of lists to the array() function. We will now select each item of the matrix one at a time, as shown in the following code snippet. Remember, the indices are numbered starting from 0.

In: a[0,0]
Out: 1
In: a[0,1]
Out: 2
In: a[1,0]
Out: 3
In: a[1,1]
Out: 4

As you can see, selecting elements of the array is pretty simple. For the array a, we just use the notation a[m,n], where m and n are the indices of the item in the array.