test_CRSMatrix.cpp

#include <catch2/catch.hpp>

#include <CRSMatrix.hpp>

// Instantiate to ensure full coverage is performed
template class SparseMatrixDescriptor<int, uint8_t>;

TEST_CASE("CRSMatrix", "[algebra]")
{
  SECTION("CRSMatrix")
  {
    SECTION("matrix size")
    {
      SparseMatrixDescriptor<int, uint8_t> S{5};
      S(0, 2) = 3;
      S(1, 2) = 11;
      S(1, 1) = 1;
      S(3, 0) = 5;
      S(3, 1) = -3;
      S(4, 1) = 1;
      S(2, 2) = 4;
      S(4, 3) = 2;
      S(4, 4) = -2;

      CRSMatrix<int, uint8_t> A{S};

      REQUIRE(A.numberOfRows() == S.numberOfRows());
    }

    SECTION("matrix vector product (simple)")
    {
      SparseMatrixDescriptor<int, uint8_t> S{5};
      S(0, 2) = 3;
      S(1, 2) = 11;
      S(1, 1) = 1;
      S(3, 0) = 5;
      S(3, 1) = -3;
      S(4, 1) = 1;
      S(2, 2) = 4;
      S(4, 3) = 2;
      S(4, 4) = -2;

      CRSMatrix<int, uint8_t> A{S};

      Vector<int> x{A.numberOfRows()};
      x    = 0;
      x[0] = 1;

      Vector<int> y = A * x;
      REQUIRE(y[0] == 0);
      REQUIRE(y[1] == 0);
      REQUIRE(y[2] == 0);
      REQUIRE(y[3] == 5);
      REQUIRE(y[4] == 0);

      x    = 0;
      x[1] = 2;

      y = A * x;
      REQUIRE(y[0] == 0);
      REQUIRE(y[1] == 2);
      REQUIRE(y[2] == 0);
      REQUIRE(y[3] == -6);
      REQUIRE(y[4] == 2);

      x    = 0;
      x[2] = -1;

      y = A * x;
      REQUIRE(y[0] == -3);
      REQUIRE(y[1] == -11);
      REQUIRE(y[2] == -4);
      REQUIRE(y[3] == 0);
      REQUIRE(y[4] == 0);

      x    = 0;
      x[3] = 3;

      y = A * x;
      REQUIRE(y[0] == 0);
      REQUIRE(y[1] == 0);
      REQUIRE(y[2] == 0);
      REQUIRE(y[3] == 0);
      REQUIRE(y[4] == 6);

      x    = 0;
      x[4] = 1;

      y = A * x;
      REQUIRE(y[0] == 0);
      REQUIRE(y[1] == 0);
      REQUIRE(y[2] == 0);
      REQUIRE(y[3] == 0);
      REQUIRE(y[4] == -2);
    }

    SECTION("matrix vector product (complet)")
    {
      SparseMatrixDescriptor<int, uint8_t> S{4};
      S(0, 0) = 1;
      S(0, 1) = 2;
      S(0, 2) = 3;
      S(0, 3) = 4;
      S(1, 0) = 5;
      S(1, 1) = 6;
      S(1, 2) = 7;
      S(1, 3) = 8;
      S(2, 0) = 9;
      S(2, 1) = 10;
      S(2, 2) = 11;
      S(2, 3) = 12;
      S(3, 0) = 13;
      S(3, 1) = 14;
      S(3, 2) = 15;
      S(3, 3) = 16;

      CRSMatrix<int, uint8_t> A{S};

      Vector<int> x{A.numberOfRows()};
      x[0] = 1;
      x[1] = 2;
      x[2] = 3;
      x[3] = 4;

      Vector<int> y = A * x;
      REQUIRE(y[0] == 30);
      REQUIRE(y[1] == 70);
      REQUIRE(y[2] == 110);
      REQUIRE(y[3] == 150);
    }
  }
}