fixed multi-kernel perform test unit-test

src/shogun/statistical_testing/internals/KernelManager.cpp

@@ -137,16 +137,21 @@ void KernelManager::restore_kernel_at(size_t i)
 
 bool KernelManager::same_distance_type() const
 {
+	ASSERT(num_kernels()>0);
 	bool same=false;
 	EDistanceType distance_type=D_UNKNOWN;
 	for (size_t i=0; i<num_kernels(); ++i)
 	{
 		CShiftInvariantKernel* shift_invariant_kernel=dynamic_cast<CShiftInvariantKernel*>(kernel_at(i));
 		if (shift_invariant_kernel!=nullptr)
 		{
+			auto current_distance_type=shift_invariant_kernel->get_distance_type();
 			if (distance_type==D_UNKNOWN)
-				distance_type=shift_invariant_kernel->get_distance_type();
-			else if (distance_type==shift_invariant_kernel->get_distance_type())
+			{
+				distance_type=current_distance_type;
+				same=true;
+			}
+			else if (distance_type==current_distance_type)
 				same=true;
 			else
 			{

tests/unit/statistical_testing/QuadraticTimeMMD_unittest.cc

@@ -535,11 +535,13 @@ TEST(QuadraticTimeMMD, compute_multiple)
 
 TEST(QuadraticTimeMMD, perform_test_multiple)
 {
-	const index_t m=20;
-	const index_t n=20;
+	const index_t m=8;
+	const index_t n=12;
 	const index_t dim=1;
 	const index_t num_kernels=10;
 	const float64_t alpha=0.05;
+	const index_t num_null_samples=200;
+	const index_t cache_size=10;
 
 	float64_t difference=0.5;
 
@@ -550,21 +552,23 @@ TEST(QuadraticTimeMMD, perform_test_multiple)
 	CFeatures* feat_q=gen_q->get_streamed_features(n);
 
 	auto mmd=some<CQuadraticTimeMMD>(feat_p, feat_q);
+	mmd->set_num_null_samples(num_null_samples);
 	for (auto i=0, sigma=-5; i<num_kernels; ++i, sigma+=1)
 	{
 		float64_t tau=pow(2, sigma);
-		mmd->multikernel()->add_kernel(new CGaussianKernel(10, tau));
+		mmd->multikernel()->add_kernel(new CGaussianKernel(cache_size, tau));
 	}
 	sg_rand->set_seed(12345);
 	SGVector<bool> rejections_multiple=mmd->multikernel()->perform_test(alpha);
 
 	SGVector<bool> rejections_single(num_kernels);
 	for (auto i=0, sigma=-5; i<num_kernels; ++i, sigma+=1)
 	{
-		sg_rand->set_seed(12345);
 		auto mmd2=some<CQuadraticTimeMMD>(feat_p, feat_q);
+		mmd2->set_num_null_samples(num_null_samples);
 		float64_t tau=pow(2, sigma);
-		mmd2->set_kernel(new CGaussianKernel(10, tau));
+		mmd2->set_kernel(new CGaussianKernel(cache_size, tau));
+		sg_rand->set_seed(12345);
 		rejections_single[i]=mmd2->perform_test(alpha);
 	}