Addition with Matrices¶

matrix_sum(matrix_one, matrix_two)¶

Calculates the sum of two matrices

Parameters

matrix_one (list of lists of int or float) – List of lists of numbers representing a matrix
matrix_two (list of lists of int or float) – List of lists of numbers representing a matrix

Raises

TypeError – Arguments must be 2-dimensional lists
TypeError – Elements nested within arguments must be integers or floats
ValueError – Both arguments must contain the same amount of lists
ValueError – First list within first argument and first list within second argument must contain the same amount of elements

Returns

matrix – List of lists in which each inner element is the sum of the corresponding elements from the input matrices

Return type

list of lists of int or float

Notes

First matrix: \(\mathbf{A} = \begin{bmatrix} a_{1,1} & a_{1,2} & \cdots & a_{1,n} \\ a_{2,1} & a_{2,2} & \cdots & a_{2,n} \\ \cdots & \cdots & \cdots & \cdots \\ a_{m,1} & a_{m,2} & \cdots & a_{m,n} \end{bmatrix}\)
Second matrix: \(\mathbf{B} = \begin{bmatrix} b_{1,1} & b_{1,2} & \cdots & b_{1,n} \\ b_{2,1} & b_{2,2} & \cdots & b_{2,n} \\ \cdots & \cdots & \cdots & \cdots \\ b_{m,1} & b_{m,2} & \cdots & b_{m,n} \end{bmatrix}\)
Sum of matrices: \(\mathbf{A} + \mathbf{B} = \begin{bmatrix} a_{1,1} + b_{1,1} & a_{1,2} + b_{1,2} & \cdots & a_{1,n} + b_{1,n} \\ a_{2,1} + b_{2,1} & a_{2,2} + b_{2,2} & \cdots & a_{2,n} + b_{2,n} \\ \cdots & \cdots & \cdots & \cdots \\ a_{m,1} + b_{m,1} & a_{m,2} + b_{m,2} & \cdots & a_{m,n} + b_{m,n} \end{bmatrix}\)
Matrix Addition

Examples

Import matrix_sum function from regressions library

>>> from regressions.matrices.addition import matrix_sum

Add [[1, 2, 3], [4, 5, 6]] and [[2, 3, 5], [7, 11, 13]]

>>> matrix_2x3 = matrix_sum([[1, 2, 3], [4, 5, 6]], [[2, 3, 5], [7, 11, 13]])
>>> print(matrix_2x3)
[[3, 5, 8], [11, 16, 19]]

Add [[-2, 5], [7, -1]] and [[8, 2], [-3, 4]]

>>> matrix_2x2 = matrix_sum([[-2, 5], [7, -1]], [[8, 2], [-3, 4]])
>>> print(matrix_2x2)
[[6, 7], [4, 3]]