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Functions
dormlq.c File Reference

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Functions

int dormlq_fla (char *side, char *trans, integer *m, integer *n, integer *k, doublereal *a, integer *lda, doublereal *tau, doublereal *c__, integer *ldc, doublereal *work, integer *lwork, integer *info)
 

Function Documentation

◆ dormlq_fla()

int dormlq_fla ( char *  side,
char *  trans,
integer m,
integer n,
integer k,
doublereal a,
integer lda,
doublereal tau,
doublereal c__,
integer ldc,
doublereal work,
integer lwork,
integer info 
)
168 {
169  /* System generated locals */
170  integer a_dim1, a_offset, c_dim1, c_offset, i__1, i__2, i__4, i__5;
171  char ch__1[2];
172  /* Builtin functions */
173  /* Subroutine */
174 
175  /* Local variables */
176  integer i__;
177  doublereal t[4160] /* was [65][64] */
178  ;
179  integer i1, i2, i3, ib, ic, jc, nb, mi, ni, nq, nw, iws;
180  logical left;
181  extern logical lsame_(char *, char *);
182  integer nbmin, iinfo;
183  extern /* Subroutine */
184  int dorml2_fla(char *, char *, integer *, integer *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *, doublereal *, integer *), dlarfb_(char *, char *, char *, char *, integer *, integer *, integer *, doublereal *, integer *, doublereal *, integer *, doublereal *, integer *, doublereal *, integer *), dlarft_(char *, char *, integer *, integer *, doublereal *, integer *, doublereal *, doublereal *, integer *), xerbla_(char *, integer *);
185  extern integer ilaenv_(integer *, char *, char *, integer *, integer *, integer *, integer *);
186  logical notran;
187  integer ldwork;
188  char transt[1];
189  integer lwkopt;
190  logical lquery;
191  /* -- LAPACK computational routine (version 3.4.0) -- */
192  /* -- LAPACK is a software package provided by Univ. of Tennessee, -- */
193  /* -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- */
194  /* November 2011 */
195  /* .. Scalar Arguments .. */
196  /* .. */
197  /* .. Array Arguments .. */
198  /* .. */
199  /* ===================================================================== */
200  /* .. Parameters .. */
201  /* .. */
202  /* .. Local Scalars .. */
203  /* .. */
204  /* .. Local Arrays .. */
205  /* .. */
206  /* .. External Functions .. */
207  /* .. */
208  /* .. External Subroutines .. */
209  /* .. */
210  /* .. Intrinsic Functions .. */
211  /* .. */
212  /* .. Executable Statements .. */
213  /* Test the input arguments */
214  /* Parameter adjustments */
215  a_dim1 = *lda;
216  a_offset = 1 + a_dim1;
217  a -= a_offset;
218  --tau;
219  c_dim1 = *ldc;
220  c_offset = 1 + c_dim1;
221  c__ -= c_offset;
222  --work;
223  /* Function Body */
224  *info = 0;
225  left = lsame_(side, "L");
226  notran = lsame_(trans, "N");
227  lquery = *lwork == -1;
228  /* NQ is the order of Q and NW is the minimum dimension of WORK */
229  if (left)
230  {
231  nq = *m;
232  nw = *n;
233  }
234  else
235  {
236  nq = *n;
237  nw = *m;
238  }
239  if (! left && ! lsame_(side, "R"))
240  {
241  *info = -1;
242  }
243  else if (! notran && ! lsame_(trans, "T"))
244  {
245  *info = -2;
246  }
247  else if (*m < 0)
248  {
249  *info = -3;
250  }
251  else if (*n < 0)
252  {
253  *info = -4;
254  }
255  else if (*k < 0 || *k > nq)
256  {
257  *info = -5;
258  }
259  else if (*lda < max(1,*k))
260  {
261  *info = -7;
262  }
263  else if (*ldc < max(1,*m))
264  {
265  *info = -10;
266  }
267  else if (*lwork < max(1,nw) && ! lquery)
268  {
269  *info = -12;
270  }
271  if (*info == 0)
272  {
273  /* Determine the block size. NB may be at most NBMAX, where NBMAX */
274  /* is used to define the local array T. */
275  /* Computing MIN */
276  i__1 = 64;
277  i__2 = ilaenv_(&c__1, "DORMLQ", ch__1, m, n, k, &c_n1); // , expr subst
278  nb = min(i__1,i__2);
279  lwkopt = max(1,nw) * nb;
280  work[1] = (doublereal) lwkopt;
281  }
282  if (*info != 0)
283  {
284  i__1 = -(*info);
285  xerbla_("DORMLQ", &i__1);
286  return 0;
287  }
288  else if (lquery)
289  {
290  return 0;
291  }
292  /* Quick return if possible */
293  if (*m == 0 || *n == 0 || *k == 0)
294  {
295  work[1] = 1.;
296  return 0;
297  }
298  nbmin = 2;
299  ldwork = nw;
300  if (nb > 1 && nb < *k)
301  {
302  iws = nw * nb;
303  if (*lwork < iws)
304  {
305  nb = *lwork / ldwork;
306  /* Computing MAX */
307  i__1 = 2;
308  i__2 = ilaenv_(&c__2, "DORMLQ", ch__1, m, n, k, &c_n1); // , expr subst
309  nbmin = max(i__1,i__2);
310  }
311  }
312  else
313  {
314  iws = nw;
315  }
316  if (nb < nbmin || nb >= *k)
317  {
318  /* Use unblocked code */
319  dorml2_fla(side, trans, m, n, k, &a[a_offset], lda, &tau[1], &c__[ c_offset], ldc, &work[1], &iinfo);
320  }
321  else
322  {
323  /* Use blocked code */
324  if (left && notran || ! left && ! notran)
325  {
326  i1 = 1;
327  i2 = *k;
328  i3 = nb;
329  }
330  else
331  {
332  i1 = (*k - 1) / nb * nb + 1;
333  i2 = 1;
334  i3 = -nb;
335  }
336  if (left)
337  {
338  ni = *n;
339  jc = 1;
340  }
341  else
342  {
343  mi = *m;
344  ic = 1;
345  }
346  if (notran)
347  {
348  *(unsigned char *)transt = 'T';
349  }
350  else
351  {
352  *(unsigned char *)transt = 'N';
353  }
354  i__1 = i2;
355  i__2 = i3;
356  for (i__ = i1;
357  i__2 < 0 ? i__ >= i__1 : i__ <= i__1;
358  i__ += i__2)
359  {
360  /* Computing MIN */
361  i__4 = nb;
362  i__5 = *k - i__ + 1; // , expr subst
363  ib = min(i__4,i__5);
364  /* Form the triangular factor of the block reflector */
365  /* H = H(i) H(i+1) . . . H(i+ib-1) */
366  i__4 = nq - i__ + 1;
367  dlarft_("Forward", "Rowwise", &i__4, &ib, &a[i__ + i__ * a_dim1], lda, &tau[i__], t, &c__65);
368  if (left)
369  {
370  /* H or H**T is applied to C(i:m,1:n) */
371  mi = *m - i__ + 1;
372  ic = i__;
373  }
374  else
375  {
376  /* H or H**T is applied to C(1:m,i:n) */
377  ni = *n - i__ + 1;
378  jc = i__;
379  }
380  /* Apply H or H**T */
381  dlarfb_(side, transt, "Forward", "Rowwise", &mi, &ni, &ib, &a[i__ + i__ * a_dim1], lda, t, &c__65, &c__[ic + jc * c_dim1], ldc, &work[1], &ldwork);
382  /* L10: */
383  }
384  }
385  work[1] = (doublereal) lwkopt;
386  return 0;
387  /* End of DORMLQ */
388 }
double doublereal
Definition: FLA_f2c.h:31
int integer
Definition: FLA_f2c.h:25
int logical
Definition: FLA_f2c.h:36
int dorml2_fla(char *side, char *trans, integer *m, integer *n, integer *k, doublereal *a, integer *lda, doublereal *tau, doublereal *c__, integer *ldc, doublereal *work, integer *info)
Definition: dorml2.c:148

References dorml2_fla().