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# include <cppad/cppad.hpp>
# include <cppad/speed/det_by_lu.hpp>
bool JacLuDet()
{ bool ok = true;
using namespace CppAD;
size_t n = 2;
// object for computing determinants
det_by_lu<ADComplex> Det(n);
// independent and dependent variable vectors
CPPAD_TEST_VECTOR<ADComplex> X(n * n);
CPPAD_TEST_VECTOR<ADComplex> D(1);
// value of the independent variable
size_t i;
for(i = 0; i < n * n; i++)
X[i] = Complex(int(i), -int(i));
// set the independent variables
Independent(X);
// compute the determinant
D[0] = Det(X);
// create the function object
ADFun<Complex> f(X, D);
// argument value
CPPAD_TEST_VECTOR<Complex> x( n * n );
for(i = 0; i < n * n; i++)
x[i] = Complex(2 * i, i);
// first derivative of the determinant
CPPAD_TEST_VECTOR<Complex> J( n * n );
J = f.Jacobian(x);
/*
f(x) = x[0] * x[3] - x[1] * x[2]
*/
Complex Jtrue[] = { x[3], -x[2], -x[1], x[0] };
for( i = 0; i < n*n; i++)
ok &= NearEqual( Jtrue[i], J[i], 1e-10 , 1e-10 );
return ok;
}