Fix CRSMatrix::operator-()

src/algebra/CRSMatrix.hpp

@@ -123,12 +123,12 @@ class CRSMatrix
           ++i_row_B;
         } else if (A_column_idx < B_column_idx) {
           column_indices[i_value] = A_column_idx;
-          values[i_value]         = A.m_values[i_row_A];
+          values[i_value]         = BinOp()(A.m_values[i_row_A], 0);
           ++i_row_A;
         } else {
           Assert(B_column_idx < A_column_idx);
           column_indices[i_value] = B_column_idx;
-          values[i_value]         = B.m_values[i_row_B];
+          values[i_value]         = BinOp()(0, B.m_values[i_row_B]);
           ++i_row_B;
         }
         ++i_value;

tests/test_CRSMatrix.cpp

@@ -240,8 +240,8 @@ TEST_CASE("CRSMatrix", "[algebra]")
     std::ostringstream ost;
     ost << A - B;
 
-    std::string ref = R"(0| 0:2 1:2 2:3
-1| 0:-2 1:6 2:3
+    std::string ref = R"(0| 0:2 1:2 2:-3
+1| 0:-2 1:6 2:-3
 2| 0:2 2:-11 3:12
 3| 0:10 3:8
 )";
@@ -327,10 +327,10 @@ TEST_CASE("CRSMatrix", "[algebra]")
     std::ostringstream ost;
     ost << A - B;
 
-    std::string ref = R"(0| 0:2 1:2 2:3
-1| 0:-2 1:6 2:3
+    std::string ref = R"(0| 0:2 1:2 2:-3
+1| 0:-2 1:6 2:-3
 2| 0:2 2:1
-3| 0:10 1:8 2:16
+3| 0:10 1:-8 2:16
 )";
 
     REQUIRE(ost.str() == ref);