Example 1: numpy merge arrays
>>> a = np.array([[1, 2], [3, 4]])
>>> b = np.array([[5, 6]])
>>> np.concatenate((a, b), axis=0)
array([[1, 2],
[3, 4],
[5, 6]])
>>> np.concatenate((a, b.T), axis=1)
array([[1, 2, 5],
[3, 4, 6]])
Example 2: join two numpy 2d array
import numpy as np
a = np.array([[0, 1, 3], [5, 7, 9]])
b = np.array([[0, 2, 4], [6, 8, 10]])
c = np.concatenate((a, b), axis=0)
print(c)
Output :
[[ 0 1 3]
[ 5 7 9]
[ 0 2 4]
[ 6 8 10]]
Example 3: how to add two matrices in python
matrix1 = [[0, 1, 2], [3, 4, 5], [6, 7, 8]]
matrix2 = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]
def addTheMatrix(matrix1, matrix2):
matrix1Rows = len(matrix1)
matrix2Rows = len(matrix2)
matrix1Col = len(matrix1[0])
matrix2Col = len(matrix2[0])
if(matrix1Rows != matrix2Rows or matrix1Col != matrix2Col):
return "ERROR: dimensions of the two arrays must be the same"
matrix = []
rows = []
for i in range(0, matrix1Rows):
for j in range(0, matrix2Col):
rows.append(0)
matrix.append(rows.copy())
rows = []
for i in range(0, matrix1Rows):
for j in range(0, matrix2Col):
matrix[i][j] = matrix1[i][j] + matrix2[i][j]
return matrix
print(addTheMatrix(matrix1, matrix2))
Example 4: cbind arrays python
np.c_[x,y]