Method OuterProductUpdate

JSAT/src/jsat/linear/Matrix.java:882–895

Alters the matrix A such that, A = A + c x y ' @param A the matrix to update @param x the first vector @param y the second vector @param c the scalar constant to multiply the outer product by @throws ArithmeticException if the vector dimensions are not compatible with the

(Matrix A, Vec x, Vec y, double c)

     * with the matrix <i>A</i>
     */
    public static void OuterProductUpdate(Matrix A, Vec x, Vec y, double c)
    {
        if (x.length() != A.rows() || y.length() != A.cols())
            throw new ArithmeticException("Matrix dimensions do not agree with outer product");
        if (x.isSparse())
            for (IndexValue iv : x)
                A.updateRow(iv.getIndex(), iv.getValue() * c, y);
        else
            for (int i = 0; i < x.length(); i++)
            {
                double rowCosnt = c * x.get(i);
                A.updateRow(i, rowCosnt, y);
            }
    }

    /**
     * Alters the matrix <i>A</i> such that,