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#include "rb_lapack.h"
extern VOID sgebrd_(integer* m, integer* n, real* a, integer* lda, real* d, real* e, real* tauq, real* taup, real* work, integer* lwork, integer* info);
static VALUE
rblapack_sgebrd(int argc, VALUE *argv, VALUE self){
VALUE rblapack_m;
integer m;
VALUE rblapack_a;
real *a;
VALUE rblapack_lwork;
integer lwork;
VALUE rblapack_d;
real *d;
VALUE rblapack_e;
real *e;
VALUE rblapack_tauq;
real *tauq;
VALUE rblapack_taup;
real *taup;
VALUE rblapack_work;
real *work;
VALUE rblapack_info;
integer info;
VALUE rblapack_a_out__;
real *a_out__;
integer lda;
integer n;
VALUE rblapack_options;
if (argc > 0 && TYPE(argv[argc-1]) == T_HASH) {
argc--;
rblapack_options = argv[argc];
if (rb_hash_aref(rblapack_options, sHelp) == Qtrue) {
printf("%s\n", "USAGE:\n d, e, tauq, taup, work, info, a = NumRu::Lapack.sgebrd( m, a, [:lwork => lwork, :usage => usage, :help => help])\n\n\nFORTRAN MANUAL\n SUBROUTINE SGEBRD( M, N, A, LDA, D, E, TAUQ, TAUP, WORK, LWORK, INFO )\n\n* Purpose\n* =======\n*\n* SGEBRD reduces a general real M-by-N matrix A to upper or lower\n* bidiagonal form B by an orthogonal transformation: Q**T * A * P = B.\n*\n* If m >= n, B is upper bidiagonal; if m < n, B is lower bidiagonal.\n*\n\n* Arguments\n* =========\n*\n* M (input) INTEGER\n* The number of rows in the matrix A. M >= 0.\n*\n* N (input) INTEGER\n* The number of columns in the matrix A. N >= 0.\n*\n* A (input/output) REAL array, dimension (LDA,N)\n* On entry, the M-by-N general matrix to be reduced.\n* On exit,\n* if m >= n, the diagonal and the first superdiagonal are\n* overwritten with the upper bidiagonal matrix B; the\n* elements below the diagonal, with the array TAUQ, represent\n* the orthogonal matrix Q as a product of elementary\n* reflectors, and the elements above the first superdiagonal,\n* with the array TAUP, represent the orthogonal matrix P as\n* a product of elementary reflectors;\n* if m < n, the diagonal and the first subdiagonal are\n* overwritten with the lower bidiagonal matrix B; the\n* elements below the first subdiagonal, with the array TAUQ,\n* represent the orthogonal matrix Q as a product of\n* elementary reflectors, and the elements above the diagonal,\n* with the array TAUP, represent the orthogonal matrix P as\n* a product of elementary reflectors.\n* See Further Details.\n*\n* LDA (input) INTEGER\n* The leading dimension of the array A. LDA >= max(1,M).\n*\n* D (output) REAL array, dimension (min(M,N))\n* The diagonal elements of the bidiagonal matrix B:\n* D(i) = A(i,i).\n*\n* E (output) REAL array, dimension (min(M,N)-1)\n* The off-diagonal elements of the bidiagonal matrix B:\n* if m >= n, E(i) = A(i,i+1) for i = 1,2,...,n-1;\n* if m < n, E(i) = A(i+1,i) for i = 1,2,...,m-1.\n*\n* TAUQ (output) REAL array dimension (min(M,N))\n* The scalar factors of the elementary reflectors which\n* represent the orthogonal matrix Q. See Further Details.\n*\n* TAUP (output) REAL array, dimension (min(M,N))\n* The scalar factors of the elementary reflectors which\n* represent the orthogonal matrix P. See Further Details.\n*\n* WORK (workspace/output) REAL array, dimension (MAX(1,LWORK))\n* On exit, if INFO = 0, WORK(1) returns the optimal LWORK.\n*\n* LWORK (input) INTEGER\n* The length of the array WORK. LWORK >= max(1,M,N).\n* For optimum performance LWORK >= (M+N)*NB, where NB\n* is the optimal blocksize.\n*\n* If LWORK = -1, then a workspace query is assumed; the routine\n* only calculates the optimal size of the WORK array, returns\n* this value as the first entry of the WORK array, and no error\n* message related to LWORK is issued by XERBLA.\n*\n* INFO (output) INTEGER\n* = 0: successful exit \n* < 0: if INFO = -i, the i-th argument had an illegal value.\n*\n\n* Further Details\n* ===============\n*\n* The matrices Q and P are represented as products of elementary\n* reflectors:\n*\n* If m >= n,\n*\n* Q = H(1) H(2) . . . H(n) and P = G(1) G(2) . . . G(n-1)\n*\n* Each H(i) and G(i) has the form:\n*\n* H(i) = I - tauq * v * v' and G(i) = I - taup * u * u'\n*\n* where tauq and taup are real scalars, and v and u are real vectors;\n* v(1:i-1) = 0, v(i) = 1, and v(i+1:m) is stored on exit in A(i+1:m,i);\n* u(1:i) = 0, u(i+1) = 1, and u(i+2:n) is stored on exit in A(i,i+2:n);\n* tauq is stored in TAUQ(i) and taup in TAUP(i).\n*\n* If m < n,\n*\n* Q = H(1) H(2) . . . H(m-1) and P = G(1) G(2) . . . G(m)\n*\n* Each H(i) and G(i) has the form:\n*\n* H(i) = I - tauq * v * v' and G(i) = I - taup * u * u'\n*\n* where tauq and taup are real scalars, and v and u are real vectors;\n* v(1:i) = 0, v(i+1) = 1, and v(i+2:m) is stored on exit in A(i+2:m,i);\n* u(1:i-1) = 0, u(i) = 1, and u(i+1:n) is stored on exit in A(i,i+1:n);\n* tauq is stored in TAUQ(i) and taup in TAUP(i).\n*\n* The contents of A on exit are illustrated by the following examples:\n*\n* m = 6 and n = 5 (m > n): m = 5 and n = 6 (m < n):\n*\n* ( d e u1 u1 u1 ) ( d u1 u1 u1 u1 u1 )\n* ( v1 d e u2 u2 ) ( e d u2 u2 u2 u2 )\n* ( v1 v2 d e u3 ) ( v1 e d u3 u3 u3 )\n* ( v1 v2 v3 d e ) ( v1 v2 e d u4 u4 )\n* ( v1 v2 v3 v4 d ) ( v1 v2 v3 e d u5 )\n* ( v1 v2 v3 v4 v5 )\n*\n* where d and e denote diagonal and off-diagonal elements of B, vi\n* denotes an element of the vector defining H(i), and ui an element of\n* the vector defining G(i).\n*\n* =====================================================================\n*\n\n");
return Qnil;
}
if (rb_hash_aref(rblapack_options, sUsage) == Qtrue) {
printf("%s\n", "USAGE:\n d, e, tauq, taup, work, info, a = NumRu::Lapack.sgebrd( m, a, [:lwork => lwork, :usage => usage, :help => help])\n");
return Qnil;
}
} else
rblapack_options = Qnil;
if (argc != 2 && argc != 3)
rb_raise(rb_eArgError,"wrong number of arguments (%d for 2)", argc);
rblapack_m = argv[0];
rblapack_a = argv[1];
if (argc == 3) {
rblapack_lwork = argv[2];
} else if (rblapack_options != Qnil) {
rblapack_lwork = rb_hash_aref(rblapack_options, ID2SYM(rb_intern("lwork")));
} else {
rblapack_lwork = Qnil;
}
m = NUM2INT(rblapack_m);
if (!NA_IsNArray(rblapack_a))
rb_raise(rb_eArgError, "a (2th argument) must be NArray");
if (NA_RANK(rblapack_a) != 2)
rb_raise(rb_eArgError, "rank of a (2th argument) must be %d", 2);
lda = NA_SHAPE0(rblapack_a);
n = NA_SHAPE1(rblapack_a);
if (NA_TYPE(rblapack_a) != NA_SFLOAT)
rblapack_a = na_change_type(rblapack_a, NA_SFLOAT);
a = NA_PTR_TYPE(rblapack_a, real*);
if (rblapack_lwork == Qnil)
lwork = MAX(m,n);
else {
lwork = NUM2INT(rblapack_lwork);
}
{
na_shape_t shape[1];
shape[0] = MIN(m,n);
rblapack_d = na_make_object(NA_SFLOAT, 1, shape, cNArray);
}
d = NA_PTR_TYPE(rblapack_d, real*);
{
na_shape_t shape[1];
shape[0] = MIN(m,n)-1;
rblapack_e = na_make_object(NA_SFLOAT, 1, shape, cNArray);
}
e = NA_PTR_TYPE(rblapack_e, real*);
{
na_shape_t shape[1];
shape[0] = MIN(m,n);
rblapack_tauq = na_make_object(NA_SFLOAT, 1, shape, cNArray);
}
tauq = NA_PTR_TYPE(rblapack_tauq, real*);
{
na_shape_t shape[1];
shape[0] = MIN(m,n);
rblapack_taup = na_make_object(NA_SFLOAT, 1, shape, cNArray);
}
taup = NA_PTR_TYPE(rblapack_taup, real*);
{
na_shape_t shape[1];
shape[0] = MAX(1,lwork);
rblapack_work = na_make_object(NA_SFLOAT, 1, shape, cNArray);
}
work = NA_PTR_TYPE(rblapack_work, real*);
{
na_shape_t shape[2];
shape[0] = lda;
shape[1] = n;
rblapack_a_out__ = na_make_object(NA_SFLOAT, 2, shape, cNArray);
}
a_out__ = NA_PTR_TYPE(rblapack_a_out__, real*);
MEMCPY(a_out__, a, real, NA_TOTAL(rblapack_a));
rblapack_a = rblapack_a_out__;
a = a_out__;
sgebrd_(&m, &n, a, &lda, d, e, tauq, taup, work, &lwork, &info);
rblapack_info = INT2NUM(info);
return rb_ary_new3(7, rblapack_d, rblapack_e, rblapack_tauq, rblapack_taup, rblapack_work, rblapack_info, rblapack_a);
}
void
init_lapack_sgebrd(VALUE mLapack, VALUE sH, VALUE sU, VALUE zero){
sHelp = sH;
sUsage = sU;
rblapack_ZERO = zero;
rb_define_module_function(mLapack, "sgebrd", rblapack_sgebrd, -1);
}
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