public static (int, int) Iamax(MatrixExpression a)
{
var i = a.Evaluate();
int r = Blas.iamax(i.Length, i.Array, 0, 1);
if (a is not MatrixInput)
{
i.Dispose();
}
int col = Math.DivRem(r, i.Rows, out int row);
return(row, col);
}