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Diffstat (limited to 'src/lib/lapack/dsyev.f')
| -rw-r--r-- | src/lib/lapack/dsyev.f | 211 |
1 files changed, 0 insertions, 211 deletions
diff --git a/src/lib/lapack/dsyev.f b/src/lib/lapack/dsyev.f deleted file mode 100644 index d73600a2..00000000 --- a/src/lib/lapack/dsyev.f +++ /dev/null @@ -1,211 +0,0 @@ - SUBROUTINE DSYEV( JOBZ, UPLO, N, A, LDA, W, WORK, LWORK, INFO ) -* -* -- LAPACK driver routine (version 3.1) -- -* Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd.. -* November 2006 -* -* .. Scalar Arguments .. - CHARACTER JOBZ, UPLO - INTEGER INFO, LDA, LWORK, N -* .. -* .. Array Arguments .. - DOUBLE PRECISION A( LDA, * ), W( * ), WORK( * ) -* .. -* -* Purpose -* ======= -* -* DSYEV computes all eigenvalues and, optionally, eigenvectors of a -* real symmetric matrix A. -* -* Arguments -* ========= -* -* JOBZ (input) CHARACTER*1 -* = 'N': Compute eigenvalues only; -* = 'V': Compute eigenvalues and eigenvectors. -* -* UPLO (input) CHARACTER*1 -* = 'U': Upper triangle of A is stored; -* = 'L': Lower triangle of A is stored. -* -* N (input) INTEGER -* The order of the matrix A. N >= 0. -* -* A (input/output) DOUBLE PRECISION array, dimension (LDA, N) -* On entry, the symmetric matrix A. If UPLO = 'U', the -* leading N-by-N upper triangular part of A contains the -* upper triangular part of the matrix A. If UPLO = 'L', -* the leading N-by-N lower triangular part of A contains -* the lower triangular part of the matrix A. -* On exit, if JOBZ = 'V', then if INFO = 0, A contains the -* orthonormal eigenvectors of the matrix A. -* If JOBZ = 'N', then on exit the lower triangle (if UPLO='L') -* or the upper triangle (if UPLO='U') of A, including the -* diagonal, is destroyed. -* -* LDA (input) INTEGER -* The leading dimension of the array A. LDA >= max(1,N). -* -* W (output) DOUBLE PRECISION array, dimension (N) -* If INFO = 0, the eigenvalues in ascending order. -* -* WORK (workspace/output) DOUBLE PRECISION array, dimension (MAX(1,LWORK)) -* On exit, if INFO = 0, WORK(1) returns the optimal LWORK. -* -* LWORK (input) INTEGER -* The length of the array WORK. LWORK >= max(1,3*N-1). -* For optimal efficiency, LWORK >= (NB+2)*N, -* where NB is the blocksize for DSYTRD returned by ILAENV. -* -* If LWORK = -1, then a workspace query is assumed; the routine -* only calculates the optimal size of the WORK array, returns -* this value as the first entry of the WORK array, and no error -* message related to LWORK is issued by XERBLA. -* -* INFO (output) INTEGER -* = 0: successful exit -* < 0: if INFO = -i, the i-th argument had an illegal value -* > 0: if INFO = i, the algorithm failed to converge; i -* off-diagonal elements of an intermediate tridiagonal -* form did not converge to zero. -* -* ===================================================================== -* -* .. Parameters .. - DOUBLE PRECISION ZERO, ONE - PARAMETER ( ZERO = 0.0D0, ONE = 1.0D0 ) -* .. -* .. Local Scalars .. - LOGICAL LOWER, LQUERY, WANTZ - INTEGER IINFO, IMAX, INDE, INDTAU, INDWRK, ISCALE, - $ LLWORK, LWKOPT, NB - DOUBLE PRECISION ANRM, BIGNUM, EPS, RMAX, RMIN, SAFMIN, SIGMA, - $ SMLNUM -* .. -* .. External Functions .. - LOGICAL LSAME - INTEGER ILAENV - DOUBLE PRECISION DLAMCH, DLANSY - EXTERNAL LSAME, ILAENV, DLAMCH, DLANSY -* .. -* .. External Subroutines .. - EXTERNAL DLASCL, DORGTR, DSCAL, DSTEQR, DSTERF, DSYTRD, - $ XERBLA -* .. -* .. Intrinsic Functions .. - INTRINSIC MAX, SQRT -* .. -* .. Executable Statements .. -* -* Test the input parameters. -* - WANTZ = LSAME( JOBZ, 'V' ) - LOWER = LSAME( UPLO, 'L' ) - LQUERY = ( LWORK.EQ.-1 ) -* - INFO = 0 - IF( .NOT.( WANTZ .OR. LSAME( JOBZ, 'N' ) ) ) THEN - INFO = -1 - ELSE IF( .NOT.( LOWER .OR. LSAME( UPLO, 'U' ) ) ) THEN - INFO = -2 - ELSE IF( N.LT.0 ) THEN - INFO = -3 - ELSE IF( LDA.LT.MAX( 1, N ) ) THEN - INFO = -5 - END IF -* - IF( INFO.EQ.0 ) THEN - NB = ILAENV( 1, 'DSYTRD', UPLO, N, -1, -1, -1 ) - LWKOPT = MAX( 1, ( NB+2 )*N ) - WORK( 1 ) = LWKOPT -* - IF( LWORK.LT.MAX( 1, 3*N-1 ) .AND. .NOT.LQUERY ) - $ INFO = -8 - END IF -* - IF( INFO.NE.0 ) THEN - CALL XERBLA( 'DSYEV ', -INFO ) - RETURN - ELSE IF( LQUERY ) THEN - RETURN - END IF -* -* Quick return if possible -* - IF( N.EQ.0 ) THEN - RETURN - END IF -* - IF( N.EQ.1 ) THEN - W( 1 ) = A( 1, 1 ) - WORK( 1 ) = 2 - IF( WANTZ ) - $ A( 1, 1 ) = ONE - RETURN - END IF -* -* Get machine constants. -* - SAFMIN = DLAMCH( 'Safe minimum' ) - EPS = DLAMCH( 'Precision' ) - SMLNUM = SAFMIN / EPS - BIGNUM = ONE / SMLNUM - RMIN = SQRT( SMLNUM ) - RMAX = SQRT( BIGNUM ) -* -* Scale matrix to allowable range, if necessary. -* - ANRM = DLANSY( 'M', UPLO, N, A, LDA, WORK ) - ISCALE = 0 - IF( ANRM.GT.ZERO .AND. ANRM.LT.RMIN ) THEN - ISCALE = 1 - SIGMA = RMIN / ANRM - ELSE IF( ANRM.GT.RMAX ) THEN - ISCALE = 1 - SIGMA = RMAX / ANRM - END IF - IF( ISCALE.EQ.1 ) - $ CALL DLASCL( UPLO, 0, 0, ONE, SIGMA, N, N, A, LDA, INFO ) -* -* Call DSYTRD to reduce symmetric matrix to tridiagonal form. -* - INDE = 1 - INDTAU = INDE + N - INDWRK = INDTAU + N - LLWORK = LWORK - INDWRK + 1 - CALL DSYTRD( UPLO, N, A, LDA, W, WORK( INDE ), WORK( INDTAU ), - $ WORK( INDWRK ), LLWORK, IINFO ) -* -* For eigenvalues only, call DSTERF. For eigenvectors, first call -* DORGTR to generate the orthogonal matrix, then call DSTEQR. -* - IF( .NOT.WANTZ ) THEN - CALL DSTERF( N, W, WORK( INDE ), INFO ) - ELSE - CALL DORGTR( UPLO, N, A, LDA, WORK( INDTAU ), WORK( INDWRK ), - $ LLWORK, IINFO ) - CALL DSTEQR( JOBZ, N, W, WORK( INDE ), A, LDA, WORK( INDTAU ), - $ INFO ) - END IF -* -* If matrix was scaled, then rescale eigenvalues appropriately. -* - IF( ISCALE.EQ.1 ) THEN - IF( INFO.EQ.0 ) THEN - IMAX = N - ELSE - IMAX = INFO - 1 - END IF - CALL DSCAL( IMAX, ONE / SIGMA, W, 1 ) - END IF -* -* Set WORK(1) to optimal workspace size. -* - WORK( 1 ) = LWKOPT -* - RETURN -* -* End of DSYEV -* - END |