int _spd_solve(arb_mat_t X, const arb_mat_t A, const arb_mat_t B, slong prec) { slong n, m; int result; arb_mat_t L; n = arb_mat_nrows(A); m = arb_mat_ncols(X); if (n == 0 || m == 0) return 1; n = arb_mat_nrows(A); arb_mat_init(L, n, n); result = arb_mat_cho(L, A, prec); if (result) { arb_mat_solve_cho_precomp(X, L, B, prec); } arb_mat_clear(L); return result; }
int main() { slong iter; flint_rand_t state; flint_printf("cho...."); fflush(stdout); flint_randinit(state); /* check special matrices */ { slong n; for (n = 1; n < 10; n++) { slong lprec; arb_mat_t L, A; arb_mat_init(L, n, n); arb_mat_init(A, n, n); for (lprec = 2; lprec < 10; lprec++) { int result; slong prec; prec = 1 << lprec; /* zero */ arb_mat_zero(A); result = arb_mat_cho(L, A, prec); if (result) { flint_printf("FAIL (zero):\n"); flint_printf("n = %wd, prec = %wd\n", n, prec); flint_printf("L = \n"); arb_mat_printd(L, 15); flint_printf("\n\n"); } /* negative identity */ arb_mat_one(A); arb_mat_neg(A, A); result = arb_mat_cho(L, A, prec); if (result) { flint_printf("FAIL (negative identity):\n"); flint_printf("n = %wd, prec = %wd\n", n, prec); flint_printf("L = \n"); arb_mat_printd(L, 15); flint_printf("\n\n"); } /* identity */ arb_mat_one(A); result = arb_mat_cho(L, A, prec); if (!result || !arb_mat_equal(L, A)) { flint_printf("FAIL (identity):\n"); flint_printf("n = %wd, prec = %wd\n", n, prec); flint_printf("L = \n"); arb_mat_printd(L, 15); flint_printf("\n\n"); } } arb_mat_clear(L); arb_mat_clear(A); } } for (iter = 0; iter < 10000 * arb_test_multiplier(); iter++) { fmpq_mat_t Q; arb_mat_t A, L, U, T; slong n, qbits, prec; int q_invertible, r_invertible; n = n_randint(state, 8); qbits = 1 + n_randint(state, 100); prec = 2 + n_randint(state, 202); fmpq_mat_init(Q, n, n); arb_mat_init(A, n, n); arb_mat_init(L, n, n); arb_mat_init(U, n, n); arb_mat_init(T, n, n); _fmpq_mat_randtest_positive_semidefinite(Q, state, qbits); q_invertible = fmpq_mat_is_invertible(Q); if (!q_invertible) { arb_mat_set_fmpq_mat(A, Q, prec); r_invertible = arb_mat_cho(L, A, prec); if (r_invertible) { flint_printf("FAIL: matrix is singular over Q but not over R\n"); flint_printf("n = %wd, prec = %wd\n", n, prec); flint_printf("\n"); flint_printf("Q = \n"); fmpq_mat_print(Q); flint_printf("\n\n"); flint_printf("A = \n"); arb_mat_printd(A, 15); flint_printf("\n\n"); flint_printf("L = \n"); arb_mat_printd(L, 15); flint_printf("\n\n"); } } else { /* now this must converge */ while (1) { arb_mat_set_fmpq_mat(A, Q, prec); r_invertible = arb_mat_cho(L, A, prec); if (r_invertible) { break; } else { if (prec > 10000) { flint_printf("FAIL: failed to converge at 10000 bits\n"); flint_printf("n = %wd, prec = %wd\n", n, prec); flint_printf("Q = \n"); fmpq_mat_print(Q); flint_printf("\n\n"); flint_printf("A = \n"); arb_mat_printd(A, 15); flint_printf("\n\n"); abort(); } prec *= 2; } } arb_mat_transpose(U, L); arb_mat_mul(T, L, U, prec); if (!arb_mat_contains_fmpq_mat(T, Q)) { flint_printf("FAIL (containment, iter = %wd)\n", iter); flint_printf("n = %wd, prec = %wd\n", n, prec); flint_printf("\n"); flint_printf("Q = \n"); fmpq_mat_print(Q); flint_printf("\n\n"); flint_printf("A = \n"); arb_mat_printd(A, 15); flint_printf("\n\n"); flint_printf("L = \n"); arb_mat_printd(L, 15); flint_printf("\n\n"); flint_printf("U = \n"); arb_mat_printd(U, 15); flint_printf("\n\n"); flint_printf("L*U = \n"); arb_mat_printd(T, 15); flint_printf("\n\n"); abort(); } } fmpq_mat_clear(Q); arb_mat_clear(A); arb_mat_clear(L); arb_mat_clear(U); arb_mat_clear(T); } flint_randclear(state); flint_cleanup(); flint_printf("PASS\n"); return EXIT_SUCCESS; }