np.subtract code example

Example: how to subtract two matrices in python

matrix1 = [[0, 1, 2], 
           [3, 5, 5], 
           [6, 7, 8]]

matrix2 = [[1, 2, 3], 
           [4, 5, 6], 
           [7, 8, 9]]

#output = [[-1, -1, -1], 
		# [-1, 0, -1], 
        # [-1, -1, -1]]

def subtractTheMatrix(matrix1, matrix2):
    matrix1Rows = len(matrix1)
    matrix2Rows = len(matrix2)
    matrix1Col = len(matrix1[0])
    matrix2Col = len(matrix2[0])

    #base case
    if(matrix1Rows != matrix2Rows or matrix1Col != matrix2Col):
        return "ERROR: dimensions of the two arrays must be the same"

    #make a matrix of the same size as matrix 1 and matrix 2
    matrix = []
    rows = []

    for i in range(0, matrix1Rows):
        for j in range(0, matrix2Col):
            rows.append(0)
        matrix.append(rows.copy())
        rows = []

    #loop through the two matricies and the subtraction should be placed in the
    #matrix
    for i in range(0, matrix1Rows):
        for j in range(0, matrix2Col):
            matrix[i][j] = matrix1[i][j] - matrix2[i][j]
            
    return matrix



print(subtractTheMatrix(matrix1, matrix2))