Adds sum of duplicate inserted values

This fixes #85

src/tensor.cpp

@@ -374,21 +374,50 @@ void TensorBase::pack() {
   qsort(coordinatesPtr, numCoordinates, coordSize, lexicographicalCmp);
 
 
-  // Move coords into separate arrays
+  // Move coords into separate arrays and remove duplicates
   std::vector<std::vector<int>> coordinates(order);
   for (size_t i=0; i < order; ++i) {
     coordinates[i] = std::vector<int>(numCoordinates);
   }
-
   std::vector<double> values(numCoordinates);
-  for (size_t i=0; i < numCoordinates; ++i) {
+  // Copy first coordinate-value pair
+  int* lastCoord = (int*)malloc(order * sizeof(int));
+  if (numCoordinates >= 1) {
+    int* coordComponent = (int*)coordinatesPtr;
+    for (size_t d=0; d < order; ++d) {
+      coordinates[d][0] = *coordComponent;
+      lastCoord[d] = *coordComponent;
+      coordComponent++;
+    }
+    values[0] = *((double*)coordComponent);
+  }
+  // Copy remaining coordinate-value pairs, removing duplicates
+  int j = 1;
+  int* coord = (int*)malloc(order * sizeof(int));
+  for (size_t i=1; i < numCoordinates; ++i) {
     int* coordLoc = (int*)&coordinatesPtr[i*coordSize];
     for (size_t d=0; d < order; ++d) {
-      coordinates[d][i] = *coordLoc;
+      coord[d] = *coordLoc;;
       coordLoc++;
     }
-    values[i] = *((double*)coordLoc);
+    double value = *((double*)coordLoc);
+    if (memcmp(coord, lastCoord, order*sizeof(int)) != 0) {
+      for (size_t d = 0; d < order; d++) {
+        coordinates[d][j] = coord[d];
+      }
+      values[j] = value;
+      j++;
+    }
+    else {
+      values[j-1] += value;
+    }
+  }
+  free(coord);
+  free(lastCoord);
+  for (size_t i=0; i < order; ++i) {
+    coordinates[i].resize(j);
   }
+  values.resize(j);
   taco_iassert(coordinates.size() > 0);
   this->coordinateBuffer->clear();
   this->coordinateBufferUsed = 0;

test/tensor-tests.cpp

@@ -12,14 +12,12 @@ TEST(tensor, double_scalar) {
 }
 
 TEST(tensor, double_vector) {
-  map<vector<int>, double> vals = {{{0}, 1.0},
-                                   {{2}, 2.0}};
-
   Tensor<double> a({5}, Sparse);
   ASSERT_EQ(ComponentType::Double, a.getComponentType());
   ASSERT_EQ(1u, a.getDimensions().size());
   ASSERT_EQ(5,  a.getDimensions()[0]);
 
+  map<vector<int>,double> vals = {{{0}, 1.0}, {{2}, 2.0}};
   for (auto& val : vals) {
     a.insert(val.first, val.second);
   }
@@ -36,3 +34,16 @@ TEST(tensor, double_vector) {
     ASSERT_EQ(vals.at(val.first), val.second);
   }
 }
+
+TEST(tensor, duplicates) {
+  Tensor<double> a({5,5}, Sparse);
+  a.insert({1,2}, 42.0);
+  a.insert({2,2}, 10.0);
+  a.insert({1,2}, 1.0);
+  a.pack();
+  map<vector<int>,double> vals = {{{1,2}, 43.0}, {{2,2}, 10.0}};
+  for (auto& val : a) {
+    ASSERT_TRUE(util::contains(vals, val.first));
+    ASSERT_EQ(vals.at(val.first), val.second);
+  }
+}