1 /*
2     Copyright (C) 2011 Fredrik Johansson
3 
4     This file is part of FLINT.
5 
6     FLINT is free software: you can redistribute it and/or modify it under
7     the terms of the GNU Lesser General Public License (LGPL) as published
8     by the Free Software Foundation; either version 2.1 of the License, or
9     (at your option) any later version.  See <http://www.gnu.org/licenses/>.
10 */
11 
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include "flint.h"
15 #include "fmpz_poly.h"
16 #include "fmpz_poly_mat.h"
17 
18 
19 int
main(void)20 main(void)
21 {
22     slong i;
23 
24     FLINT_TEST_INIT(state);
25 
26     flint_printf("inv....");
27     fflush(stdout);
28 
29     /* Test aliasing */
30     for (i = 0; i < 40 * flint_test_multiplier(); i++)
31     {
32         fmpz_poly_mat_t A, Ainv;
33         fmpz_poly_t den1, den2;
34         slong n, bits, deg;
35         float density;
36         int ns1, ns2;
37         int result;
38 
39         n = n_randint(state, 8);
40         deg = 1 + n_randint(state, 5);
41         bits = 1 + n_randint(state, 100);
42         density = n_randint(state, 100) * 0.01;
43 
44         fmpz_poly_mat_init(A, n, n);
45         fmpz_poly_mat_init(Ainv, n, n);
46         fmpz_poly_init(den1);
47         fmpz_poly_init(den2);
48 
49         fmpz_poly_mat_randtest_sparse(A, state, deg, bits, density);
50 
51         ns1 = fmpz_poly_mat_inv(Ainv, den1, A);
52         ns2 = fmpz_poly_mat_inv(A, den2, A);
53 
54         result = ns1 == ns2;
55 
56         if (result && ns1 != 0)
57         {
58             result = fmpz_poly_equal(den1, den2) &&
59                 fmpz_poly_mat_equal(A, Ainv);
60         }
61 
62         if (!result)
63         {
64             flint_printf("FAIL (aliasing)!\n");
65             fmpz_poly_mat_print(A, "x"); flint_printf("\n");
66             fmpz_poly_mat_print(Ainv, "x"); flint_printf("\n");
67             abort();
68         }
69 
70         fmpz_poly_mat_clear(A);
71         fmpz_poly_mat_clear(Ainv);
72         fmpz_poly_clear(den1);
73         fmpz_poly_clear(den2);
74     }
75 
76     /* Check A^(-1) = A = 1 */
77     for (i = 0; i < 100 * flint_test_multiplier(); i++)
78     {
79         fmpz_poly_mat_t A, Ainv, B, Iden;
80         fmpz_poly_t den, det;
81         slong n, bits, deg;
82         float density;
83         int nonsingular;
84 
85         n = n_randint(state, 10);
86         deg = 1 + n_randint(state, 5);
87         bits = 1 + n_randint(state, 100);
88         density = n_randint(state, 100) * 0.01;
89 
90         fmpz_poly_mat_init(A, n, n);
91         fmpz_poly_mat_init(Ainv, n, n);
92         fmpz_poly_mat_init(B, n, n);
93         fmpz_poly_mat_init(Iden, n, n);
94         fmpz_poly_init(den);
95         fmpz_poly_init(det);
96 
97         fmpz_poly_mat_randtest_sparse(A, state, deg, bits, density);
98         nonsingular = fmpz_poly_mat_inv(Ainv, den, A);
99         fmpz_poly_mat_det_interpolate(det, A);
100 
101         if (n == 0)
102         {
103             if (nonsingular == 0 || !fmpz_poly_is_one(den))
104             {
105                 flint_printf("FAIL: expected empty matrix to pass\n");
106                 abort();
107             }
108         }
109         else
110         {
111             if (!fmpz_poly_equal(den, det))
112             {
113                 fmpz_poly_neg(det, det);
114                 flint_printf("FAIL: den != det(A)\n");
115                 abort();
116             }
117 
118             fmpz_poly_mat_mul(B, Ainv, A);
119             fmpz_poly_mat_one(Iden);
120             fmpz_poly_mat_scalar_mul_fmpz_poly(Iden, Iden, den);
121 
122             if (!fmpz_poly_mat_equal(B, Iden))
123             {
124                 flint_printf("FAIL:\n");
125                 flint_printf("A:\n");
126                 fmpz_poly_mat_print(A, "x");
127                 flint_printf("Ainv:\n");
128                 fmpz_poly_mat_print(Ainv, "x");
129                 flint_printf("B:\n");
130                 fmpz_poly_mat_print(B, "x");
131                 flint_printf("den:\n");
132                 fmpz_poly_print_pretty(den, "x");
133                 abort();
134             }
135         }
136 
137         fmpz_poly_clear(den);
138         fmpz_poly_clear(det);
139         fmpz_poly_mat_clear(A);
140         fmpz_poly_mat_clear(Ainv);
141         fmpz_poly_mat_clear(B);
142         fmpz_poly_mat_clear(Iden);
143     }
144 
145     FLINT_TEST_CLEANUP(state);
146 
147     flint_printf("PASS\n");
148     return 0;
149 }
150