Annotation of rpl/lapack/lapack/dsyconv.f, revision 1.4
1.4 ! bertrand 1: *> \brief \b DSYCONV
! 2: *
! 3: * =========== DOCUMENTATION ===========
! 4: *
! 5: * Online html documentation available at
! 6: * http://www.netlib.org/lapack/explore-html/
! 7: *
! 8: *> \htmlonly
! 9: *> Download DSYCONV + dependencies
! 10: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/dsyconv.f">
! 11: *> [TGZ]</a>
! 12: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/dsyconv.f">
! 13: *> [ZIP]</a>
! 14: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/dsyconv.f">
! 15: *> [TXT]</a>
! 16: *> \endhtmlonly
! 17: *
! 18: * Definition:
! 19: * ===========
! 20: *
! 21: * SUBROUTINE DSYCONV( UPLO, WAY, N, A, LDA, IPIV, WORK, INFO )
! 22: *
! 23: * .. Scalar Arguments ..
! 24: * CHARACTER UPLO, WAY
! 25: * INTEGER INFO, LDA, N
! 26: * ..
! 27: * .. Array Arguments ..
! 28: * INTEGER IPIV( * )
! 29: * DOUBLE PRECISION A( LDA, * ), WORK( * )
! 30: * ..
! 31: *
! 32: *
! 33: *> \par Purpose:
! 34: * =============
! 35: *>
! 36: *> \verbatim
! 37: *>
! 38: *> DSYCONV convert A given by TRF into L and D and vice-versa.
! 39: *> Get Non-diag elements of D (returned in workspace) and
! 40: *> apply or reverse permutation done in TRF.
! 41: *> \endverbatim
! 42: *
! 43: * Arguments:
! 44: * ==========
! 45: *
! 46: *> \param[in] UPLO
! 47: *> \verbatim
! 48: *> UPLO is CHARACTER*1
! 49: *> Specifies whether the details of the factorization are stored
! 50: *> as an upper or lower triangular matrix.
! 51: *> = 'U': Upper triangular, form is A = U*D*U**T;
! 52: *> = 'L': Lower triangular, form is A = L*D*L**T.
! 53: *> \endverbatim
! 54: *>
! 55: *> \param[in] WAY
! 56: *> \verbatim
! 57: *> WAY is CHARACTER*1
! 58: *> = 'C': Convert
! 59: *> = 'R': Revert
! 60: *> \endverbatim
! 61: *>
! 62: *> \param[in] N
! 63: *> \verbatim
! 64: *> N is INTEGER
! 65: *> The order of the matrix A. N >= 0.
! 66: *> \endverbatim
! 67: *>
! 68: *> \param[in] A
! 69: *> \verbatim
! 70: *> A is DOUBLE PRECISION array, dimension (LDA,N)
! 71: *> The block diagonal matrix D and the multipliers used to
! 72: *> obtain the factor U or L as computed by DSYTRF.
! 73: *> \endverbatim
! 74: *>
! 75: *> \param[in] LDA
! 76: *> \verbatim
! 77: *> LDA is INTEGER
! 78: *> The leading dimension of the array A. LDA >= max(1,N).
! 79: *> \endverbatim
! 80: *>
! 81: *> \param[in] IPIV
! 82: *> \verbatim
! 83: *> IPIV is INTEGER array, dimension (N)
! 84: *> Details of the interchanges and the block structure of D
! 85: *> as determined by DSYTRF.
! 86: *> \endverbatim
! 87: *>
! 88: *> \param[out] WORK
! 89: *> \verbatim
! 90: *> WORK is DOUBLE PRECISION array, dimension (N)
! 91: *> \endverbatim
! 92: *>
! 93: *> \param[out] INFO
! 94: *> \verbatim
! 95: *> INFO is INTEGER
! 96: *> = 0: successful exit
! 97: *> < 0: if INFO = -i, the i-th argument had an illegal value
! 98: *> \endverbatim
! 99: *
! 100: * Authors:
! 101: * ========
! 102: *
! 103: *> \author Univ. of Tennessee
! 104: *> \author Univ. of California Berkeley
! 105: *> \author Univ. of Colorado Denver
! 106: *> \author NAG Ltd.
! 107: *
! 108: *> \date November 2011
! 109: *
! 110: *> \ingroup doubleSYcomputational
! 111: *
! 112: * =====================================================================
1.1 bertrand 113: SUBROUTINE DSYCONV( UPLO, WAY, N, A, LDA, IPIV, WORK, INFO )
114: *
1.4 ! bertrand 115: * -- LAPACK computational routine (version 3.4.0) --
1.1 bertrand 116: * -- LAPACK is a software package provided by Univ. of Tennessee, --
117: * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
1.4 ! bertrand 118: * November 2011
1.1 bertrand 119: *
120: * .. Scalar Arguments ..
121: CHARACTER UPLO, WAY
122: INTEGER INFO, LDA, N
123: * ..
124: * .. Array Arguments ..
125: INTEGER IPIV( * )
126: DOUBLE PRECISION A( LDA, * ), WORK( * )
127: * ..
128: *
129: * =====================================================================
130: *
131: * .. Parameters ..
132: DOUBLE PRECISION ZERO
133: PARAMETER ( ZERO = 0.0D+0 )
134: * ..
135: * .. External Functions ..
136: LOGICAL LSAME
137: EXTERNAL LSAME
138: *
139: * .. External Subroutines ..
140: EXTERNAL XERBLA
141: * .. Local Scalars ..
142: LOGICAL UPPER, CONVERT
143: INTEGER I, IP, J
144: DOUBLE PRECISION TEMP
145: * ..
146: * .. Executable Statements ..
147: *
148: INFO = 0
149: UPPER = LSAME( UPLO, 'U' )
150: CONVERT = LSAME( WAY, 'C' )
151: IF( .NOT.UPPER .AND. .NOT.LSAME( UPLO, 'L' ) ) THEN
152: INFO = -1
153: ELSE IF( .NOT.CONVERT .AND. .NOT.LSAME( WAY, 'R' ) ) THEN
154: INFO = -2
155: ELSE IF( N.LT.0 ) THEN
156: INFO = -3
157: ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
158: INFO = -5
159:
160: END IF
161: IF( INFO.NE.0 ) THEN
162: CALL XERBLA( 'DSYCONV', -INFO )
163: RETURN
164: END IF
165: *
166: * Quick return if possible
167: *
168: IF( N.EQ.0 )
169: $ RETURN
170: *
171: IF( UPPER ) THEN
172: *
173: * A is UPPER
174: *
175: * Convert A (A is upper)
176: *
177: * Convert VALUE
178: *
179: IF ( CONVERT ) THEN
180: I=N
181: WORK(1)=ZERO
182: DO WHILE ( I .GT. 1 )
183: IF( IPIV(I) .LT. 0 ) THEN
184: WORK(I)=A(I-1,I)
185: A(I-1,I)=ZERO
186: I=I-1
187: ELSE
188: WORK(I)=ZERO
189: ENDIF
190: I=I-1
191: END DO
192: *
193: * Convert PERMUTATIONS
194: *
195: I=N
196: DO WHILE ( I .GE. 1 )
197: IF( IPIV(I) .GT. 0) THEN
198: IP=IPIV(I)
199: IF( I .LT. N) THEN
200: DO 12 J= I+1,N
201: TEMP=A(IP,J)
202: A(IP,J)=A(I,J)
203: A(I,J)=TEMP
204: 12 CONTINUE
205: ENDIF
206: ELSE
207: IP=-IPIV(I)
208: IF( I .LT. N) THEN
209: DO 13 J= I+1,N
210: TEMP=A(IP,J)
211: A(IP,J)=A(I-1,J)
212: A(I-1,J)=TEMP
213: 13 CONTINUE
214: ENDIF
215: I=I-1
216: ENDIF
217: I=I-1
218: END DO
219:
220: ELSE
221: *
222: * Revert A (A is upper)
223: *
224: *
225: * Revert PERMUTATIONS
226: *
227: I=1
228: DO WHILE ( I .LE. N )
229: IF( IPIV(I) .GT. 0 ) THEN
230: IP=IPIV(I)
231: IF( I .LT. N) THEN
232: DO J= I+1,N
233: TEMP=A(IP,J)
234: A(IP,J)=A(I,J)
235: A(I,J)=TEMP
236: END DO
237: ENDIF
238: ELSE
239: IP=-IPIV(I)
240: I=I+1
241: IF( I .LT. N) THEN
242: DO J= I+1,N
243: TEMP=A(IP,J)
244: A(IP,J)=A(I-1,J)
245: A(I-1,J)=TEMP
246: END DO
247: ENDIF
248: ENDIF
249: I=I+1
250: END DO
251: *
252: * Revert VALUE
253: *
254: I=N
255: DO WHILE ( I .GT. 1 )
256: IF( IPIV(I) .LT. 0 ) THEN
257: A(I-1,I)=WORK(I)
258: I=I-1
259: ENDIF
260: I=I-1
261: END DO
262: END IF
263: ELSE
264: *
265: * A is LOWER
266: *
267: IF ( CONVERT ) THEN
268: *
269: * Convert A (A is lower)
270: *
271: *
272: * Convert VALUE
273: *
274: I=1
275: WORK(N)=ZERO
276: DO WHILE ( I .LE. N )
277: IF( I.LT.N .AND. IPIV(I) .LT. 0 ) THEN
278: WORK(I)=A(I+1,I)
279: A(I+1,I)=ZERO
280: I=I+1
281: ELSE
282: WORK(I)=ZERO
283: ENDIF
284: I=I+1
285: END DO
286: *
287: * Convert PERMUTATIONS
288: *
289: I=1
290: DO WHILE ( I .LE. N )
291: IF( IPIV(I) .GT. 0 ) THEN
292: IP=IPIV(I)
293: IF (I .GT. 1) THEN
294: DO 22 J= 1,I-1
295: TEMP=A(IP,J)
296: A(IP,J)=A(I,J)
297: A(I,J)=TEMP
298: 22 CONTINUE
299: ENDIF
300: ELSE
301: IP=-IPIV(I)
302: IF (I .GT. 1) THEN
303: DO 23 J= 1,I-1
304: TEMP=A(IP,J)
305: A(IP,J)=A(I+1,J)
306: A(I+1,J)=TEMP
307: 23 CONTINUE
308: ENDIF
309: I=I+1
310: ENDIF
311: I=I+1
312: END DO
313: ELSE
314: *
315: * Revert A (A is lower)
316: *
317: *
318: * Revert PERMUTATIONS
319: *
320: I=N
321: DO WHILE ( I .GE. 1 )
322: IF( IPIV(I) .GT. 0 ) THEN
323: IP=IPIV(I)
324: IF (I .GT. 1) THEN
325: DO J= 1,I-1
326: TEMP=A(I,J)
327: A(I,J)=A(IP,J)
328: A(IP,J)=TEMP
329: END DO
330: ENDIF
331: ELSE
332: IP=-IPIV(I)
333: I=I-1
334: IF (I .GT. 1) THEN
335: DO J= 1,I-1
336: TEMP=A(I+1,J)
337: A(I+1,J)=A(IP,J)
338: A(IP,J)=TEMP
339: END DO
340: ENDIF
341: ENDIF
342: I=I-1
343: END DO
344: *
345: * Revert VALUE
346: *
347: I=1
348: DO WHILE ( I .LE. N-1 )
349: IF( IPIV(I) .LT. ZERO ) THEN
350: A(I+1,I)=WORK(I)
351: I=I+1
352: ENDIF
353: I=I+1
354: END DO
355: END IF
356: END IF
357:
358: RETURN
359: *
360: * End of DSYCONV
361: *
362: END
CVSweb interface <joel.bertrand@systella.fr>
![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to dsyconv.f CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [local] / rpl / lapack / lapack