add: density noise backend

1 files changed, 13 insertions, 0 deletions

diff --git a/tester/main.c b/tester/main.c
index 346b16a..858be2e 100644
--- a/tester/main.c
+++ b/tester/main.c
@@ -215,5 +215,18 @@ int main(void)
 		psi_format_probability(probs[7], pbuf, sizeof pbuf));
 
 	psi_free_quantum_circuit(&ghz);
+
+	struct PsiDensityMatrix dm = psi_new_density_matrix(1);
+	printf("dm      = purity %g (pure? %d)\n", psi_purity_density_matrix(dm), psi_is_pure_density_matrix(dm, 1e-10));
+
+	struct PsiNoiseChannel bf = psi_bit_flip_channel(0.25);
+	psi_apply_noise_channel(&dm, bf, 0);
+
+	double dprobs[2];
+	psi_density_matrix_probabilities(dm, dprobs);
+	printf("noisy   = p [%g, %g], purity %g\n", dprobs[0], dprobs[1], psi_purity_density_matrix(dm));
+
+	psi_free_noise_channel(&bf);
+	psi_free_density_matrix(&dm);
 }