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task 7

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This commit is contained in:
Fredrik Robertsen
2025-10-07 12:46:37 +02:00
parent e65573abf0
commit 2126473078
1 changed files with 20 additions and 15 deletions
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exercise4/wave_2d_parallel.c
+20 -15
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@@ -114,23 +114,28 @@ void domain_save(int_t step) {
// Neumann (reflective) boundary condition
void boundary_condition(void) {
// BEGIN: T7
// Vertical ghost layers (bottom and top)
for (int_t i = 0; i < M; i++) {
U(i, -1) = U(i, 1); // bottom ghost row <- mirror of row 1
U(i, N) = U(i, N - 2); // top ghost row <- mirror of row N-2
}
// Horizontal ghost layers (left and right)
for (int_t j = 0; j < N; j++) {
U(-1, j) = U(1, j); // left ghost col <- mirror of col 1
U(M, j) = U(M - 2, j); // right ghost col <- mirror of col M-2
if (up == MPI_PROC_NULL) {
// note: -1 to handle corners automatically
for (int_t j = -1; j < local_N + 1; j++) {
U(-1, j) = U(1, j);
}
}
if (down == MPI_PROC_NULL) {
for (int_t j = -1; j < local_N + 1; j++) {
U(local_M, j) = U(local_M - 2, j);
}
}
if (left == MPI_PROC_NULL) {
for (int_t i = -1; i < local_M + 1; i++) {
U(i, -1) = U(i, 1);
}
}
if (right == MPI_PROC_NULL) {
for (int_t i = -1; i < local_M + 1; i++) {
U(i, local_N) = U(i, local_N - 2);
}
}
// Corner ghost cells (use ghost indices)
U(-1, -1) = U(1, 1); // bottom-left
U(-1, N) = U(1, N - 2); // top-left
U(M, -1) = U(M - 2, 1); // bottom-right
U(M, N) = U(M - 2, N - 2); // top-right
// END: T7
}