Matrix multiplication in solidity

Question

I am trying to implement an algorithm requiring matrix multiplication. I know I can program this in the rudimentary way similar to doing the process by hand, but I am worried about the computational costs associated with this.

In solidity, the "matrix" would just be a two-dimensional array or even just a vector.

Does anyone know of an existing implementation of matrix multiplication in solidity? I want to make sure I do this efficiently and am wondering if anyone else has established a good way of doing it. I am unable to find any library or posts on the subject.

Thanks in advance.

Answer 1

This simple method is what I will use for now as long as I know the dimensions of the matrices. Thanks.

function mat3Mult(uint[3][3] mat1, uint[3][3] mat2) private returns (uint[3][3]) { // multiplies 3x3 matrix with 3x3 matrix
        uint r1 = mat1.length; // rows of mat1
        uint c1 = mat1[0].length; // columns of mat1
        uint c2 = mat2[0].length; // columns of mat2

        uint[3][3] memory result; 

        for(uint i = 0; i < r1; ++i) {
            for(uint j = 0; j < c2; ++j) {
                for(uint k = 0; k < c1; ++k) {
                    result[i][j] += mat1[i][k] * mat2[k][j];
                }
            }
        }

        return(result);
    }