Update the test to cover both double and vector<double> case (0e373195) · Commits · ORNL Quantum Computing Institute / qcor

examples/simple/gradients_optimization.cpp

+48 −13

Original line number	Diff line number	Diff line
		@@ -4,6 +4,13 @@ __qpu__ void ansatz(qreg q, double theta) {
		CX(q[1], q[0]);
		}

		// Ansatz that takes a vector
		__qpu__ void ansatz_vec(qreg q, std::vector<double> angles) {
		X(q[0]);
		Ry(q[1], angles[0]);
		CX(q[1], q[0]);
		}

		int main(int argc, char **argv) {
		// Allocate 2 qubits
		auto q = qalloc(2);
		@@ -16,11 +23,16 @@ int main(int argc, char **argv) {
		auto H = 5.907 - 2.1433 * X(0) * X(1) - 2.1433 * Y(0) * Y(1) + .21829 * Z(0) -
		6.125 * Z(1);

		// Create the Optimizer.
		// Simple case 1: variational ansatz takes a single double
		{
		// Create the Optimizer (gradient-based)
		auto optimizer = createOptimizer("nlopt", {{"nlopt-optimizer", "l-bfgs"}});
		OptFunction opt_function(
		[&](const std::vector<double> &x, std::vector<double> &dx) {
		auto q = qalloc(2);
		// Using kernel auto-gradient helper
		// Note: ansatz takes a single double argument => x[0]
		// Compile error if using the wrong signature.
		auto exp = ansatz::autograd(H, dx, q, x[0]);
		print("<E(", x[0], ") = ", exp);
		return exp;
		@@ -29,4 +41,27 @@ int main(int argc, char **argv) {

		auto [energy, opt_params] = optimizer->optimize(opt_function);
		print(energy);
		qcor_expect(std::abs(energy + 1.74886) < 0.1);
		}

		// Simple case 2: variational ansatz takes a vector<double>
		{
		// Create the Optimizer (gradient-based)
		auto optimizer = createOptimizer("nlopt", {{"nlopt-optimizer", "l-bfgs"}});
		OptFunction opt_function(
		[&](const std::vector<double> &x, std::vector<double> &dx) {
		auto q = qalloc(2);
		// Using kernel auto-gradient helper
		// Note: ansatz_vec takes a vector of double; hence just forward the
		// whole vector.
		auto exp = ansatz_vec::autograd(H, dx, q, x);
		print("<E(", x[0], ") = ", exp);
		return exp;
		},
		n_variational_params);

		auto [energy, opt_params] = optimizer->optimize(opt_function);
		print(energy);
		qcor_expect(std::abs(energy + 1.74886) < 0.1);
		}
		}