vector sum_if

Former-commit-id: 67b2ef9ff6

src/utility/vector.h

@@ -249,6 +249,22 @@ namespace storm {
                 return filter(values,  fnc);
             }
             
+            /**
+             * Sum the entries from values that are set to one in the filter vector.
+             * @param values
+             * @param filter
+             * @return The sum of the values with a corresponding one in the filter.
+             */
+            template<typename VT>
+            VT sum_if(std::vector<VT> const& values, storm::storage::BitVector const& filter) {
+                assert(values.size() >= filter.size());
+                VT sum = storm::utility::zero<VT>();
+                for(uint_fast64_t i : filter) {
+                    sum += values[i];
+                }    
+                return sum;
+            }
+            
             /*!
              * Reduces the given source vector by selecting an element according to the given filter out of each row group.
              *

test/functional/utility/VectorTest.cpp

@@ -0,0 +1,14 @@
+#include "gtest/gtest.h"
+#include "storm-config.h"
+#include "src/storage/BitVector.h"
+#include "src/utility/vector.h"
+
+TEST(VectorTest, sum_if) {
+    std::vector<double> a = {1.0, 2.0, 4.0, 8.0, 16.0};
+    storm::storage::BitVector f1(5, {2,4});
+    storm::storage::BitVector f2(5, {3,4});
+    
+    ASSERT_EQ(20.0, storm::utility::vector::sum_if(a, f1));
+    ASSERT_EQ(24.0, storm::utility::vector::sum_if(a, f2));
+    
+}