diff options
author | julie <julielangou@users.noreply.github.com> | 2011-10-06 06:53:11 +0000 |
---|---|---|
committer | julie <julielangou@users.noreply.github.com> | 2011-10-06 06:53:11 +0000 |
commit | e1d39294aee16fa6db9ba079b14442358217db71 (patch) | |
tree | 30e5aa04c1f6596991fda5334f63dfb9b8027849 /SRC/dsbtrd.f | |
parent | 5fe0466a14e395641f4f8a300ecc9dcb8058081b (diff) | |
download | lapack-e1d39294aee16fa6db9ba079b14442358217db71.tar.gz lapack-e1d39294aee16fa6db9ba079b14442358217db71.tar.bz2 lapack-e1d39294aee16fa6db9ba079b14442358217db71.zip |
Integrating Doxygen in comments
Diffstat (limited to 'SRC/dsbtrd.f')
-rw-r--r-- | SRC/dsbtrd.f | 235 |
1 files changed, 159 insertions, 76 deletions
diff --git a/SRC/dsbtrd.f b/SRC/dsbtrd.f index e7a3a53d..853682e8 100644 --- a/SRC/dsbtrd.f +++ b/SRC/dsbtrd.f @@ -1,10 +1,167 @@ +*> \brief \b DSBTRD +* +* =========== DOCUMENTATION =========== +* +* Online html documentation available at +* http://www.netlib.org/lapack/explore-html/ +* +* Definition +* ========== +* +* SUBROUTINE DSBTRD( VECT, UPLO, N, KD, AB, LDAB, D, E, Q, LDQ, +* WORK, INFO ) +* +* .. Scalar Arguments .. +* CHARACTER UPLO, VECT +* INTEGER INFO, KD, LDAB, LDQ, N +* .. +* .. Array Arguments .. +* DOUBLE PRECISION AB( LDAB, * ), D( * ), E( * ), Q( LDQ, * ), +* $ WORK( * ) +* .. +* +* Purpose +* ======= +* +*>\details \b Purpose: +*>\verbatim +*> +*> DSBTRD reduces a real symmetric band matrix A to symmetric +*> tridiagonal form T by an orthogonal similarity transformation: +*> Q**T * A * Q = T. +*> +*>\endverbatim +* +* Arguments +* ========= +* +*> \param[in] VECT +*> \verbatim +*> VECT is CHARACTER*1 +*> = 'N': do not form Q; +*> = 'V': form Q; +*> = 'U': update a matrix X, by forming X*Q. +*> \endverbatim +*> +*> \param[in] UPLO +*> \verbatim +*> UPLO is CHARACTER*1 +*> = 'U': Upper triangle of A is stored; +*> = 'L': Lower triangle of A is stored. +*> \endverbatim +*> +*> \param[in] N +*> \verbatim +*> N is INTEGER +*> The order of the matrix A. N >= 0. +*> \endverbatim +*> +*> \param[in] KD +*> \verbatim +*> KD is INTEGER +*> The number of superdiagonals of the matrix A if UPLO = 'U', +*> or the number of subdiagonals if UPLO = 'L'. KD >= 0. +*> \endverbatim +*> +*> \param[in,out] AB +*> \verbatim +*> AB is DOUBLE PRECISION array, dimension (LDAB,N) +*> On entry, the upper or lower triangle of the symmetric band +*> matrix A, stored in the first KD+1 rows of the array. The +*> j-th column of A is stored in the j-th column of the array AB +*> as follows: +*> if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j; +*> if UPLO = 'L', AB(1+i-j,j) = A(i,j) for j<=i<=min(n,j+kd). +*> On exit, the diagonal elements of AB are overwritten by the +*> diagonal elements of the tridiagonal matrix T; if KD > 0, the +*> elements on the first superdiagonal (if UPLO = 'U') or the +*> first subdiagonal (if UPLO = 'L') are overwritten by the +*> off-diagonal elements of T; the rest of AB is overwritten by +*> values generated during the reduction. +*> \endverbatim +*> +*> \param[in] LDAB +*> \verbatim +*> LDAB is INTEGER +*> The leading dimension of the array AB. LDAB >= KD+1. +*> \endverbatim +*> +*> \param[out] D +*> \verbatim +*> D is DOUBLE PRECISION array, dimension (N) +*> The diagonal elements of the tridiagonal matrix T. +*> \endverbatim +*> +*> \param[out] E +*> \verbatim +*> E is DOUBLE PRECISION array, dimension (N-1) +*> The off-diagonal elements of the tridiagonal matrix T: +*> E(i) = T(i,i+1) if UPLO = 'U'; E(i) = T(i+1,i) if UPLO = 'L'. +*> \endverbatim +*> +*> \param[in,out] Q +*> \verbatim +*> Q is DOUBLE PRECISION array, dimension (LDQ,N) +*> On entry, if VECT = 'U', then Q must contain an N-by-N +*> matrix X; if VECT = 'N' or 'V', then Q need not be set. +*> \endverbatim +*> \verbatim +*> On exit: +*> if VECT = 'V', Q contains the N-by-N orthogonal matrix Q; +*> if VECT = 'U', Q contains the product X*Q; +*> if VECT = 'N', the array Q is not referenced. +*> \endverbatim +*> +*> \param[in] LDQ +*> \verbatim +*> LDQ is INTEGER +*> The leading dimension of the array Q. +*> LDQ >= 1, and LDQ >= N if VECT = 'V' or 'U'. +*> \endverbatim +*> +*> \param[out] WORK +*> \verbatim +*> WORK is DOUBLE PRECISION array, dimension (N) +*> \endverbatim +*> +*> \param[out] INFO +*> \verbatim +*> INFO is INTEGER +*> = 0: successful exit +*> < 0: if INFO = -i, the i-th argument had an illegal value +*> \endverbatim +*> +* +* Authors +* ======= +* +*> \author Univ. of Tennessee +*> \author Univ. of California Berkeley +*> \author Univ. of Colorado Denver +*> \author NAG Ltd. +* +*> \date November 2011 +* +*> \ingroup doubleOTHERcomputational +* +* +* Further Details +* =============== +*>\details \b Further \b Details +*> \verbatim +*> +*> Modified by Linda Kaufman, Bell Labs. +*> +*> \endverbatim +*> +* ===================================================================== SUBROUTINE DSBTRD( VECT, UPLO, N, KD, AB, LDAB, D, E, Q, LDQ, $ WORK, INFO ) * -* -- LAPACK routine (version 3.2) -- +* -- LAPACK computational routine (version 3.2) -- * -- LAPACK is a software package provided by Univ. of Tennessee, -- * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..-- -* November 2006 +* November 2011 * * .. Scalar Arguments .. CHARACTER UPLO, VECT @@ -15,80 +172,6 @@ $ WORK( * ) * .. * -* Purpose -* ======= -* -* DSBTRD reduces a real symmetric band matrix A to symmetric -* tridiagonal form T by an orthogonal similarity transformation: -* Q**T * A * Q = T. -* -* Arguments -* ========= -* -* VECT (input) CHARACTER*1 -* = 'N': do not form Q; -* = 'V': form Q; -* = 'U': update a matrix X, by forming X*Q. -* -* 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. -* -* KD (input) INTEGER -* The number of superdiagonals of the matrix A if UPLO = 'U', -* or the number of subdiagonals if UPLO = 'L'. KD >= 0. -* -* AB (input/output) DOUBLE PRECISION array, dimension (LDAB,N) -* On entry, the upper or lower triangle of the symmetric band -* matrix A, stored in the first KD+1 rows of the array. The -* j-th column of A is stored in the j-th column of the array AB -* as follows: -* if UPLO = 'U', AB(kd+1+i-j,j) = A(i,j) for max(1,j-kd)<=i<=j; -* if UPLO = 'L', AB(1+i-j,j) = A(i,j) for j<=i<=min(n,j+kd). -* On exit, the diagonal elements of AB are overwritten by the -* diagonal elements of the tridiagonal matrix T; if KD > 0, the -* elements on the first superdiagonal (if UPLO = 'U') or the -* first subdiagonal (if UPLO = 'L') are overwritten by the -* off-diagonal elements of T; the rest of AB is overwritten by -* values generated during the reduction. -* -* LDAB (input) INTEGER -* The leading dimension of the array AB. LDAB >= KD+1. -* -* D (output) DOUBLE PRECISION array, dimension (N) -* The diagonal elements of the tridiagonal matrix T. -* -* E (output) DOUBLE PRECISION array, dimension (N-1) -* The off-diagonal elements of the tridiagonal matrix T: -* E(i) = T(i,i+1) if UPLO = 'U'; E(i) = T(i+1,i) if UPLO = 'L'. -* -* Q (input/output) DOUBLE PRECISION array, dimension (LDQ,N) -* On entry, if VECT = 'U', then Q must contain an N-by-N -* matrix X; if VECT = 'N' or 'V', then Q need not be set. -* -* On exit: -* if VECT = 'V', Q contains the N-by-N orthogonal matrix Q; -* if VECT = 'U', Q contains the product X*Q; -* if VECT = 'N', the array Q is not referenced. -* -* LDQ (input) INTEGER -* The leading dimension of the array Q. -* LDQ >= 1, and LDQ >= N if VECT = 'V' or 'U'. -* -* WORK (workspace) DOUBLE PRECISION array, dimension (N) -* -* INFO (output) INTEGER -* = 0: successful exit -* < 0: if INFO = -i, the i-th argument had an illegal value -* -* Further Details -* =============== -* -* Modified by Linda Kaufman, Bell Labs. -* * ===================================================================== * * .. Parameters .. |