summaryrefslogtreecommitdiff
path: root/SRC/zppequ.f
diff options
context:
space:
mode:
authorjulie <julielangou@users.noreply.github.com>2011-10-06 06:53:11 +0000
committerjulie <julielangou@users.noreply.github.com>2011-10-06 06:53:11 +0000
commite1d39294aee16fa6db9ba079b14442358217db71 (patch)
tree30e5aa04c1f6596991fda5334f63dfb9b8027849 /SRC/zppequ.f
parent5fe0466a14e395641f4f8a300ecc9dcb8058081b (diff)
downloadlapack-e1d39294aee16fa6db9ba079b14442358217db71.tar.gz
lapack-e1d39294aee16fa6db9ba079b14442358217db71.tar.bz2
lapack-e1d39294aee16fa6db9ba079b14442358217db71.zip
Integrating Doxygen in comments
Diffstat (limited to 'SRC/zppequ.f')
-rw-r--r--SRC/zppequ.f160
1 files changed, 111 insertions, 49 deletions
diff --git a/SRC/zppequ.f b/SRC/zppequ.f
index 92478f9a..c1de9f48 100644
--- a/SRC/zppequ.f
+++ b/SRC/zppequ.f
@@ -1,9 +1,118 @@
+*> \brief \b ZPPEQU
+*
+* =========== DOCUMENTATION ===========
+*
+* Online html documentation available at
+* http://www.netlib.org/lapack/explore-html/
+*
+* Definition
+* ==========
+*
+* SUBROUTINE ZPPEQU( UPLO, N, AP, S, SCOND, AMAX, INFO )
+*
+* .. Scalar Arguments ..
+* CHARACTER UPLO
+* INTEGER INFO, N
+* DOUBLE PRECISION AMAX, SCOND
+* ..
+* .. Array Arguments ..
+* DOUBLE PRECISION S( * )
+* COMPLEX*16 AP( * )
+* ..
+*
+* Purpose
+* =======
+*
+*>\details \b Purpose:
+*>\verbatim
+*>
+*> ZPPEQU computes row and column scalings intended to equilibrate a
+*> Hermitian positive definite matrix A in packed storage and reduce
+*> its condition number (with respect to the two-norm). S contains the
+*> scale factors, S(i)=1/sqrt(A(i,i)), chosen so that the scaled matrix
+*> B with elements B(i,j)=S(i)*A(i,j)*S(j) has ones on the diagonal.
+*> This choice of S puts the condition number of B within a factor N of
+*> the smallest possible condition number over all possible diagonal
+*> scalings.
+*>
+*>\endverbatim
+*
+* Arguments
+* =========
+*
+*> \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] AP
+*> \verbatim
+*> AP is COMPLEX*16 array, dimension (N*(N+1)/2)
+*> The upper or lower triangle of the Hermitian matrix A, packed
+*> columnwise in a linear array. The j-th column of A is stored
+*> in the array AP as follows:
+*> if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
+*> if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n.
+*> \endverbatim
+*>
+*> \param[out] S
+*> \verbatim
+*> S is DOUBLE PRECISION array, dimension (N)
+*> If INFO = 0, S contains the scale factors for A.
+*> \endverbatim
+*>
+*> \param[out] SCOND
+*> \verbatim
+*> SCOND is DOUBLE PRECISION
+*> If INFO = 0, S contains the ratio of the smallest S(i) to
+*> the largest S(i). If SCOND >= 0.1 and AMAX is neither too
+*> large nor too small, it is not worth scaling by S.
+*> \endverbatim
+*>
+*> \param[out] AMAX
+*> \verbatim
+*> AMAX is DOUBLE PRECISION
+*> Absolute value of largest matrix element. If AMAX is very
+*> close to overflow or very close to underflow, the matrix
+*> should be scaled.
+*> \endverbatim
+*>
+*> \param[out] INFO
+*> \verbatim
+*> INFO is INTEGER
+*> = 0: successful exit
+*> < 0: if INFO = -i, the i-th argument had an illegal value
+*> > 0: if INFO = i, the i-th diagonal element is nonpositive.
+*> \endverbatim
+*>
+*
+* Authors
+* =======
+*
+*> \author Univ. of Tennessee
+*> \author Univ. of California Berkeley
+*> \author Univ. of Colorado Denver
+*> \author NAG Ltd.
+*
+*> \date November 2011
+*
+*> \ingroup complex16OTHERcomputational
+*
+* =====================================================================
SUBROUTINE ZPPEQU( UPLO, N, AP, S, SCOND, AMAX, 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
@@ -15,53 +124,6 @@
COMPLEX*16 AP( * )
* ..
*
-* Purpose
-* =======
-*
-* ZPPEQU computes row and column scalings intended to equilibrate a
-* Hermitian positive definite matrix A in packed storage and reduce
-* its condition number (with respect to the two-norm). S contains the
-* scale factors, S(i)=1/sqrt(A(i,i)), chosen so that the scaled matrix
-* B with elements B(i,j)=S(i)*A(i,j)*S(j) has ones on the diagonal.
-* This choice of S puts the condition number of B within a factor N of
-* the smallest possible condition number over all possible diagonal
-* scalings.
-*
-* Arguments
-* =========
-*
-* 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.
-*
-* AP (input) COMPLEX*16 array, dimension (N*(N+1)/2)
-* The upper or lower triangle of the Hermitian matrix A, packed
-* columnwise in a linear array. The j-th column of A is stored
-* in the array AP as follows:
-* if UPLO = 'U', AP(i + (j-1)*j/2) = A(i,j) for 1<=i<=j;
-* if UPLO = 'L', AP(i + (j-1)*(2n-j)/2) = A(i,j) for j<=i<=n.
-*
-* S (output) DOUBLE PRECISION array, dimension (N)
-* If INFO = 0, S contains the scale factors for A.
-*
-* SCOND (output) DOUBLE PRECISION
-* If INFO = 0, S contains the ratio of the smallest S(i) to
-* the largest S(i). If SCOND >= 0.1 and AMAX is neither too
-* large nor too small, it is not worth scaling by S.
-*
-* AMAX (output) DOUBLE PRECISION
-* Absolute value of largest matrix element. If AMAX is very
-* close to overflow or very close to underflow, the matrix
-* should be scaled.
-*
-* INFO (output) INTEGER
-* = 0: successful exit
-* < 0: if INFO = -i, the i-th argument had an illegal value
-* > 0: if INFO = i, the i-th diagonal element is nonpositive.
-*
* =====================================================================
*
* .. Parameters ..