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[Adam Getchell <>]

Hello all,

For the following code:

void make_23_move(Delaunay* D3, std::vector<Cell_handle>* three_one,

                     std::vector<Cell_handle>* two_two) {

  // Pick a random (2,2)

  unsigned choice = generate_random_unsigned(three_one->size());

  std::cout << "We're picking (3,1) vector " << choice << std::endl;

  Cell_handle to_be_moved = (*three_one)[choice];

  for (size_t i = 0; i < 4; i++) {

    if (D3->flip(to_be_moved, i)) {

      // Delaunay::flip_flippable(to_be_moved,0)

      std::cout << "Facet " << i << " was flippable." << std::endl;

      break;

    } else {

      std::cout << "Facet " << i << " was not flippable." << std::endl;

    }

  }

}

From: https://github.com/acgetchell/CDT-plusplus/blob/master/src/S3ErgodicMoves.h

Invoked in the test:

TEST_F(S3ErgodicMoves, MakeA23Move) {

  unsigned number_of_vertices_before = T.number_of_vertices();

  unsigned N3_31_before = three_one.size();

  unsigned N3_22_before = two_two.size();

  unsigned N3_13_before = one_three.size();

  std::cout << "Number of (2,2) simplices before = " << N3_22_before

            << std::endl;

  make_23_move(&T, &three_one, &two_two);

  // Now look at changes

  reclassify_3_simplices(&T, &three_one, &two_two, &one_three);

  unsigned N3_31_after = three_one.size();

  unsigned N3_22_after = two_two.size();

  unsigned N3_13_after = one_three.size();

  EXPECT_TRUE(T.is_valid())

  << "Triangulation is invalid.";

From: https://github.com/acgetchell/CDT-plusplus/blob/master/unittests/S3ErgodicMovesTest.cpp

I've run these tests a couple dozen times, and every time there is a flippable edge the triangulation is invalidated, e.g.:

Repeating all tests (iteration 9) . . .

Note: Google Test filter = S3ErgodicMoves.MakeA23Move

[==========] Running 1 test from 1 test case.

[----------] Global test environment set-up.

[----------] 1 test from S3ErgodicMoves

[ RUN      ] S3ErgodicMoves.MakeA23Move

Generating universe ...

Pass #1

Fixing foliation....

Pass #2

Fixing foliation....

Pass #3

Fixing foliation....

Pass #4

Fixing foliation....

Pass #5

Fixing foliation....

Classifying simplices....

Valid foliation: true

Delaunay triangulation has 95251 cells.

There are 29713 (3,1) simplices and 35628 (2,2) simplices and 29910 (1,3) simplices.

Number of (2,2) simplices before = 35628

Random number is 27858

We're picking (3,1) vector 27858

Facet 0 was flippable.

Classifying simplices....

../unittests/S3ErgodicMovesTest.cpp:82: Failure

Value of: T.is_valid()

  Actual: false

Expected: true

Triangulation is invalid.

[  FAILED  ] S3ErgodicMoves.MakeA23Move (2229 ms)

[----------] 1 test from S3ErgodicMoves (2229 ms total)

[----------] Global test environment tear-down

[==========] 1 test from 1 test case ran. (2229 ms total)

[  PASSED  ] 0 tests.

[  FAILED  ] 1 test, listed below:

[  FAILED  ] S3ErgodicMoves.MakeA23Move

 1 FAILED TEST

--

Adam Getchell

about.me/adamgetchell

"Invincibility is in oneself, vulnerability in the opponent." -- Sun Tzu