Fix cuda resize kernel if image_dim > neuron_dim

Related to #33

Author: BerndDoser

src/CudaLib/resize_kernel.h

@@ -22,7 +22,7 @@ void resize_kernel(T *dst, T const *src, uint32_t dst_dim, uint32_t src_dim, uin
 
     uint32_t src_margin = 0, dst_margin = 0;
     if (src_dim < dst_dim) dst_margin = (dst_dim - src_dim) * 0.5;
-    else if (src_dim > dst_dim) src_margin = (src_dim - dst_dim) / 0.5;
+    else if (src_dim > dst_dim) src_margin = (src_dim - dst_dim) * 0.5;
 
     dst[(i + dst_margin) * dst_dim + (j + dst_margin)] =
     src[(i + src_margin) * src_dim + (j + src_margin)];

src/SelfOrganizingMapLib/Trainer.h

@@ -133,6 +133,7 @@ class Trainer<SOMLayout, DataLayout, T, false> : public TrainerBase<SOMLayout, D
             this->use_flip, this->interpolation, neuron_dim);
 
 #ifdef PRINT_DEBUG
+        std::cout << "spatial_transformed_images" << std::endl;
         for (auto&& e : spatial_transformed_images) std::cout << e << " ";
         std::cout << std::endl;
 #endif
@@ -237,6 +238,7 @@ class Trainer<SOMLayout, DataLayout, T, true> : public TrainerBase<SOMLayout, Da
             data.get_dimension()[0], neuron_dim, this->use_flip, this->interpolation, d_cos_alpha, d_sin_alpha);
 
 #ifdef PRINT_DEBUG
+        std::cout << "spatial_transformed_images" << std::endl;
         thrust::host_vector<T> spatial_transformed_images = d_spatial_transformed_images;
         for (auto&& e : spatial_transformed_images) std::cout << e << " ";
         std::cout << std::endl;

test/CudaTest/CMakeLists.txt

@@ -11,6 +11,7 @@ cuda_add_executable(
     compare_trainer_mixed.cu
     mapper.cu
     mixed_precision.cu
+    resize.cu
     rotate_90_degrees_list.cu
     update_neurons.cu
 )

test/CudaTest/compare_trainer_cpu.cu

@@ -88,4 +88,8 @@ INSTANTIATE_TEST_CASE_P(TrainerCompareTest_all, compare_trainer_cpu,
        ,TrainerCompareTestData(2,  64, 100, 100, 360,  true)
        ,TrainerCompareTestData(2,  64, 100,  45, 360,  true)
        ,TrainerCompareTestData(2, 124,  91,  64, 360,  true)
+       ,TrainerCompareTestData(2,   4,   2,   2,   1, false)
+       ,TrainerCompareTestData(2,   4,   2,   2,   8, false)
+       ,TrainerCompareTestData(2,   4,   2,   2,   1,  true)
+       ,TrainerCompareTestData(2,   4,   2,   2,   8,  true)
 ));

test/CudaTest/resize.cu

@@ -0,0 +1,39 @@
+/**
+ * @file   CudaTest/resize.cu
+ * @date   Nov 14, 2018
+ * @author Bernd Doser, HITS gGmbH
+ */
+
+#include <gtest/gtest.h>
+#include <thrust/device_vector.h>
+#include <thrust/host_vector.h>
+#include <vector>
+
+#include "CudaLib/resize_kernel.h"
+
+using namespace pink;
+
+TEST(ResizeTest, small)
+{
+    uint32_t neuron_dim = 2;
+    uint32_t image_dim = 4;
+    uint32_t min_dim = 2;
+
+    std::vector<uint32_t> image{ 0,  1,  2,  3,
+                                 4,  5,  6,  7,
+                                 8,  9, 10, 11,
+                                12, 13, 14, 15};
+
+    thrust::device_vector<uint32_t> d_image = image;
+    thrust::device_vector<uint32_t> d_resized_image(4);
+
+    dim3 dim_block(32, 32);
+    dim3 dim_grid(1, 1);
+
+    resize_kernel<<<dim_grid, dim_block>>>(thrust::raw_pointer_cast(&d_resized_image[0]),
+        thrust::raw_pointer_cast(&d_image[0]), neuron_dim, image_dim, min_dim);
+
+    thrust::host_vector<uint32_t> result = d_resized_image;
+    thrust::host_vector<uint32_t> expected = std::vector<uint32_t>{5, 6, 9, 10};
+    EXPECT_EQ(expected, result);
+}