I am a new C++ user and I am also doing a major in Maths so thought I would try implement a simple calculator. I got some code off the internet and now I just need help to multiply elements of 2 matrices or vectors.

Matrixf multiply(Matrixf const& left, Matrixf const& right) {

    // error check
    if (left.ncols() != right.nrows()) {
        throw std::runtime_error("Unable to multiply: matrix dimensions not agree.");
    }

    /* I have all the other part of the code for matrix*/

    /** Now I am not sure how to implement multiplication of vector or matrix.**/


    Matrixf ret(1, 1);

    return ret;
}