# include <vector>
# include <cstddef>
# include <cppad/utility/vector.hpp>
# include <cppad/speed/mat_sum_sq.hpp>
bool mat_sum_sq()
{ bool ok = true;
double x_00, x_01, x_10, x_11, check;
// dimension of the matrices x, y, and the result z
size_t n = 2;
CppAD::vector<double> x(n * n), y(n * n), z(1);
// x = [ 1 2 ; 3 4 ]
x[0] = x_00 = 1.;
x[1] = x_01 = 2.;
x[2] = x_10 = 3.;
x[3] = x_11 = 4.;
// compute y = x * x and z = sum of elements in y
CppAD::mat_sum_sq(n, x, y, z);
// check y_00
check = x_00 * x_00 + x_01 * x_10;
ok &= (check == y[0]);
// check y_01
check = x_00 * x_01 + x_01 * x_11;
ok &= (check == y[1]);
// check y_10
check = x_10 * x_00 + x_11 * x_10;
ok &= (check == y[2]);
// check y_11
check = x_10 * x_01 + x_11 * x_11;
ok &= (check == y[3]);
// check z
check = y[0] + y[1] + y[2] + y[3];
ok &= (check == z[0]);
return ok;
}