numpy.concatenate() in Python

numpy.concatenate() in Python

The numpy.concatenate() function joins a sequence of arrays along an existing axis.

Syntax

numpy.concatenate((a1, a2, ...), axis=0, out=None)

Parameter

a1, a2, … : This parameter represents the sequence of the array where they must have the same shape, except in the dimension corresponding to the axis .

axis: It is an optional parameter which takes integer values, and by default, it is 0. It represents the axis along which the arrays will be joined. If the axis is none, arrays are flattened before use.

out: This parameter represents the destination to place the result.

Return

This function returns the concatenated array.

Example 1

# Python program explaining
# numpy.concatenate() function   
import numpy as np
val = np.array([[11,12],[13,14]])
print ('I array:')
print (val)
val2 = np.array([[25,26],[27,28]])
print ('II array:')
print (val2 )
# both the arrays are of same dimensions
print ('Joining the two arrays along axis 0:' )
print (np.concatenate((val,val2)))
print ('Joining the two arrays along axis 1:' )
print (np.concatenate((val,val2),axis = 1))

Output

I array:
[[11 12]
[13 14]]
II array:
[[25 26]
[27 28]]
Joining the two arrays along axis 0:
[[11 12]
[13 14]
[25 26]
[27 28]]
Joining the two arrays along axis 1:
[[11 12 25 26]
[13 14 27 28]]