Contents
NumPy – Initialize Array with Range of Numbers
To initialise an array with a range of numbers in NumPy, you can use numpy.arange() function.
The syntax to call numpy.arange() function is
numpy.arange(start, stop, step)
where
- start [mandatory] is the starting of the range.
- stop [mandatory] is the ending of the range. stop is not inclusive in the returned array.
- step [optional] is the difference between adjacent numbers in the range.
The function returns a numpy array with elements starting from start, in steps of step value step, until stop.
Examples
1. Create 1D numpy array with numbers from 10 to 19
In the following program, we create one dimensional numpy array with a range of numbers from 10 upto 20(20 not included).
Output
[10 11 12 13 14 15 16 17 18 19]
2. Create numpy array with numbers from 10 to 50 in steps of 5
In the following program, we create one dimensional numpy array with a range of numbers from 10 to 50 in steps of 5.
Output
[10 15 20 25 30 35 40 45]
3. Create 2D numpy array with a range of numbers
In the following program, we create a two dimensional array with a range of numbers starting from 1, with an array shape of (4, 5).
Since we need 4*5=20 elements to create an array of shape (4, 5), and start of the range is 1, ending of the range must be (4*5)+1.
Python Program
import numpy as np
shape = (4, 5)
arr = np.arange(1, (4*5)+1).reshape(shape)
print(arr)
Run Code CopyOutput
[[ 1 2 3 4 5]
[ 6 7 8 9 10]
[11 12 13 14 15]
[16 17 18 19 20]]
Summary
In this NumPy Tutorial, we learned how to create or initialise a numpy array with a range of numbers using numpy.arange() function.