Annotation of rpl/lapack/lapack/zhetri2.f, revision 1.2
1.2 ! bertrand 1: *> \brief \b ZHETRI2
! 2: *
! 3: * =========== DOCUMENTATION ===========
! 4: *
! 5: * Online html documentation available at
! 6: * http://www.netlib.org/lapack/explore-html/
! 7: *
! 8: *> \htmlonly
! 9: *> Download ZHETRI2 + dependencies
! 10: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.tgz?format=tgz&filename=/lapack/lapack_routine/zhetri2.f">
! 11: *> [TGZ]</a>
! 12: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.zip?format=zip&filename=/lapack/lapack_routine/zhetri2.f">
! 13: *> [ZIP]</a>
! 14: *> <a href="http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=/lapack/lapack_routine/zhetri2.f">
! 15: *> [TXT]</a>
! 16: *> \endhtmlonly
! 17: *
! 18: * Definition:
! 19: * ===========
! 20: *
! 21: * SUBROUTINE ZHETRI2( UPLO, N, A, LDA, IPIV, WORK, LWORK, INFO )
! 22: *
! 23: * .. Scalar Arguments ..
! 24: * CHARACTER UPLO
! 25: * INTEGER INFO, LDA, LWORK, N
! 26: * ..
! 27: * .. Array Arguments ..
! 28: * INTEGER IPIV( * )
! 29: * COMPLEX*16 A( LDA, * ), WORK( * )
! 30: * ..
! 31: *
! 32: *
! 33: *> \par Purpose:
! 34: * =============
! 35: *>
! 36: *> \verbatim
! 37: *>
! 38: *> ZHETRI2 computes the inverse of a COMPLEX*16 hermitian indefinite matrix
! 39: *> A using the factorization A = U*D*U**T or A = L*D*L**T computed by
! 40: *> ZHETRF. ZHETRI2 set the LEADING DIMENSION of the workspace
! 41: *> before calling ZHETRI2X that actually computes the inverse.
! 42: *> \endverbatim
! 43: *
! 44: * Arguments:
! 45: * ==========
! 46: *
! 47: *> \param[in] UPLO
! 48: *> \verbatim
! 49: *> UPLO is CHARACTER*1
! 50: *> Specifies whether the details of the factorization are stored
! 51: *> as an upper or lower triangular matrix.
! 52: *> = 'U': Upper triangular, form is A = U*D*U**T;
! 53: *> = 'L': Lower triangular, form is A = L*D*L**T.
! 54: *> \endverbatim
! 55: *>
! 56: *> \param[in] N
! 57: *> \verbatim
! 58: *> N is INTEGER
! 59: *> The order of the matrix A. N >= 0.
! 60: *> \endverbatim
! 61: *>
! 62: *> \param[in,out] A
! 63: *> \verbatim
! 64: *> A is COMPLEX*16 array, dimension (LDA,N)
! 65: *> On entry, the NB diagonal matrix D and the multipliers
! 66: *> used to obtain the factor U or L as computed by ZHETRF.
! 67: *>
! 68: *> On exit, if INFO = 0, the (symmetric) inverse of the original
! 69: *> matrix. If UPLO = 'U', the upper triangular part of the
! 70: *> inverse is formed and the part of A below the diagonal is not
! 71: *> referenced; if UPLO = 'L' the lower triangular part of the
! 72: *> inverse is formed and the part of A above the diagonal is
! 73: *> not referenced.
! 74: *> \endverbatim
! 75: *>
! 76: *> \param[in] LDA
! 77: *> \verbatim
! 78: *> LDA is INTEGER
! 79: *> The leading dimension of the array A. LDA >= max(1,N).
! 80: *> \endverbatim
! 81: *>
! 82: *> \param[in] IPIV
! 83: *> \verbatim
! 84: *> IPIV is INTEGER array, dimension (N)
! 85: *> Details of the interchanges and the NB structure of D
! 86: *> as determined by ZHETRF.
! 87: *> \endverbatim
! 88: *>
! 89: *> \param[out] WORK
! 90: *> \verbatim
! 91: *> WORK is COMPLEX*16 array, dimension (N+NB+1)*(NB+3)
! 92: *> \endverbatim
! 93: *>
! 94: *> \param[in] LWORK
! 95: *> \verbatim
! 96: *> LWORK is INTEGER
! 97: *> The dimension of the array WORK.
! 98: *> WORK is size >= (N+NB+1)*(NB+3)
! 99: *> If LDWORK = -1, then a workspace query is assumed; the routine
! 100: *> calculates:
! 101: *> - the optimal size of the WORK array, returns
! 102: *> this value as the first entry of the WORK array,
! 103: *> - and no error message related to LDWORK is issued by XERBLA.
! 104: *> \endverbatim
! 105: *>
! 106: *> \param[out] INFO
! 107: *> \verbatim
! 108: *> INFO is INTEGER
! 109: *> = 0: successful exit
! 110: *> < 0: if INFO = -i, the i-th argument had an illegal value
! 111: *> > 0: if INFO = i, D(i,i) = 0; the matrix is singular and its
! 112: *> inverse could not be computed.
! 113: *> \endverbatim
! 114: *
! 115: * Authors:
! 116: * ========
! 117: *
! 118: *> \author Univ. of Tennessee
! 119: *> \author Univ. of California Berkeley
! 120: *> \author Univ. of Colorado Denver
! 121: *> \author NAG Ltd.
! 122: *
! 123: *> \date November 2011
! 124: *
! 125: *> \ingroup complex16HEcomputational
! 126: *
! 127: * =====================================================================
1.1 bertrand 128: SUBROUTINE ZHETRI2( UPLO, N, A, LDA, IPIV, WORK, LWORK, INFO )
129: *
1.2 ! bertrand 130: * -- LAPACK computational routine (version 3.4.0) --
1.1 bertrand 131: * -- LAPACK is a software package provided by Univ. of Tennessee, --
132: * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
1.2 ! bertrand 133: * November 2011
1.1 bertrand 134: *
135: * .. Scalar Arguments ..
136: CHARACTER UPLO
137: INTEGER INFO, LDA, LWORK, N
138: * ..
139: * .. Array Arguments ..
140: INTEGER IPIV( * )
141: COMPLEX*16 A( LDA, * ), WORK( * )
142: * ..
143: *
144: * =====================================================================
145: *
146: * .. Local Scalars ..
147: LOGICAL UPPER, LQUERY
148: INTEGER MINSIZE, NBMAX
149: * ..
150: * .. External Functions ..
151: LOGICAL LSAME
152: INTEGER ILAENV
153: EXTERNAL LSAME, ILAENV
154: * ..
155: * .. External Subroutines ..
156: EXTERNAL ZHETRI2X
157: * ..
158: * .. Executable Statements ..
159: *
160: * Test the input parameters.
161: *
162: INFO = 0
163: UPPER = LSAME( UPLO, 'U' )
164: LQUERY = ( LWORK.EQ.-1 )
165: * Get blocksize
166: NBMAX = ILAENV( 1, 'ZHETRF', UPLO, N, -1, -1, -1 )
167: IF ( NBMAX .GE. N ) THEN
168: MINSIZE = N
169: ELSE
170: MINSIZE = (N+NBMAX+1)*(NBMAX+3)
171: END IF
172: *
173: IF( .NOT.UPPER .AND. .NOT.LSAME( UPLO, 'L' ) ) THEN
174: INFO = -1
175: ELSE IF( N.LT.0 ) THEN
176: INFO = -2
177: ELSE IF( LDA.LT.MAX( 1, N ) ) THEN
178: INFO = -4
179: ELSE IF (LWORK .LT. MINSIZE .AND. .NOT.LQUERY ) THEN
180: INFO = -7
181: END IF
182: *
183: * Quick return if possible
184: *
185: *
186: IF( INFO.NE.0 ) THEN
187: CALL XERBLA( 'ZHETRI2', -INFO )
188: RETURN
189: ELSE IF( LQUERY ) THEN
190: WORK(1)=MINSIZE
191: RETURN
192: END IF
193: IF( N.EQ.0 )
194: $ RETURN
195:
196: IF( NBMAX .GE. N ) THEN
197: CALL ZHETRI( UPLO, N, A, LDA, IPIV, WORK, INFO )
198: ELSE
199: CALL ZHETRI2X( UPLO, N, A, LDA, IPIV, WORK, NBMAX, INFO )
200: END IF
201: RETURN
202: *
203: * End of ZHETRI2
204: *
205: END
CVSweb interface <joel.bertrand@systella.fr>
![[BACK]](/cvsweb/icons/back.gif){kind=icon}
Return to zhetri2.f CVS log ![[TXT]](/cvsweb/icons/text.gif){kind=icon}
![[DIR]](/cvsweb/icons/dir.gif){kind=icon}
Up to [local] / rpl / lapack / lapack