1 /* emacs edit mode for this file is -*- C++ -*- */
2
3 /**
4 *
5 * @file cf_hnf.cc
6 *
7 * HNF/LLL of NTL
8 *
9 * Header file: cf_hnf.h
10 *
11 **/
12
13
14 #include "config.h"
15
16 #include "canonicalform.h"
17 #include "cf_defs.h"
18 #include "cf_hnf.h"
19 #include "cf_util.h"
20
21 #ifdef HAVE_NTL
22 #include "NTLconvert.h"
23 #include <NTL/mat_ZZ.h>
24 #include <NTL/HNF.h>
25 #include <NTL/LLL.h>
26 #endif
27
28 #ifdef HAVE_FLINT
29 #include "FLINTconvert.h"
30 #endif
31
32 /**
33 * The input matrix A is an n x m matrix of rank m (so n >= m), and D
34 * is a multiple of the determinant of the lattice L spanned by the
35 * rows of A. W is computed as the Hermite Normal Form of A; that is,
36 * W is the unique m x m matrix whose rows span L, such that
37 *
38 * - W is lower triangular,
39 * - the diagonal entries are positive,
40 * - any entry below the diagonal is a non-negative number
41 * strictly less than the diagonal entry in its column.
42 *
43 **/
cf_HNF(CFMatrix & A)44 CFMatrix* cf_HNF(CFMatrix& A)
45 {
46 #ifdef HAVE_FLINT
47 fmpz_mat_t FLINTM;
48 convertFacCFMatrix2Fmpz_mat_t(FLINTM,A);
49 fmpz_mat_hnf(FLINTM,FLINTM);
50 CFMatrix *r=convertFmpz_mat_t2FacCFMatrix(FLINTM);
51 fmpz_mat_clear(FLINTM);
52 return r;
53 #elif defined(HAVE_NTL)
54 mat_ZZ *AA=convertFacCFMatrix2NTLmat_ZZ(A);
55 ZZ DD=convertFacCF2NTLZZ(determinant(A,A.rows()));
56 mat_ZZ WW;
57 HNF(WW,*AA,DD);
58 delete AA;
59 return convertNTLmat_ZZ2FacCFMatrix(WW);
60 #else
61 factoryError("NTL/FLINT missing: cf_HNF");
62 return NULL; // avoid warning
63 #endif
64 }
65
cf_LLL(CFMatrix & A)66 CFMatrix* cf_LLL(CFMatrix& A)
67 {
68 #ifdef HAVE_FLINT
69 fmpz_mat_t FLINTM;
70 convertFacCFMatrix2Fmpz_mat_t(FLINTM,A);
71 fmpq_t delta,eta;
72 fmpq_init(delta); fmpq_set_si(delta,1,1);
73 fmpq_init(eta); fmpq_set_si(eta,3,4);
74 fmpz_mat_lll_storjohann(FLINTM,delta,eta);
75 CFMatrix *r=convertFmpz_mat_t2FacCFMatrix(FLINTM);
76 fmpz_mat_clear(FLINTM);
77 return r;
78 #elif defined(HAVE_NTL)
79 mat_ZZ *AA=convertFacCFMatrix2NTLmat_ZZ(A);
80 ZZ det2;
81 LLL(det2,*AA,0L);
82 CFMatrix *r= convertNTLmat_ZZ2FacCFMatrix(*AA);
83 delete AA;
84 return r;
85 #else
86 factoryError("NTL/FLINT missing: cf_LLL");
87 return NULL; // avoid warning
88 #endif
89 }
90