dhsein.f.html
来自「famous linear algebra library (LAPACK) p」· HTML 代码 · 共 436 行 · 第 1/3 页
HTML
436 行
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>dhsein.f</title>
<meta name="generator" content="emacs 21.3.1; htmlfontify 0.20">
<style type="text/css"><!--
body { background: rgb(255, 255, 255); color: rgb(0, 0, 0); font-style: normal; font-weight: 500; font-stretch: normal; font-family: adobe-courier; font-size: 11pt; text-decoration: none; }
span.default { background: rgb(255, 255, 255); color: rgb(0, 0, 0); font-style: normal; font-weight: 500; font-stretch: normal; font-family: adobe-courier; font-size: 11pt; text-decoration: none; }
span.default a { background: rgb(255, 255, 255); color: rgb(0, 0, 0); font-style: normal; font-weight: 500; font-stretch: normal; font-family: adobe-courier; font-size: 11pt; text-decoration: underline; }
span.string { color: rgb(188, 143, 143); background: rgb(255, 255, 255); font-style: normal; font-weight: 500; font-stretch: normal; font-family: adobe-courier; font-size: 11pt; text-decoration: none; }
span.string a { color: rgb(188, 143, 143); background: rgb(255, 255, 255); font-style: normal; font-weight: 500; font-stretch: normal; font-family: adobe-courier; font-size: 11pt; text-decoration: underline; }
span.comment { color: rgb(178, 34, 34); background: rgb(255, 255, 255); font-style: normal; font-weight: 500; font-stretch: normal; font-family: adobe-courier; font-size: 11pt; text-decoration: none; }
span.comment a { color: rgb(178, 34, 34); background: rgb(255, 255, 255); font-style: normal; font-weight: 500; font-stretch: normal; font-family: adobe-courier; font-size: 11pt; text-decoration: underline; }
--></style>
</head>
<body>
<pre>
SUBROUTINE <a name="DHSEIN.1"></a><a href="dhsein.f.html#DHSEIN.1">DHSEIN</a>( SIDE, EIGSRC, INITV, SELECT, N, H, LDH, WR, WI,
$ VL, LDVL, VR, LDVR, MM, M, WORK, IFAILL,
$ IFAILR, INFO )
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> -- LAPACK routine (version 3.1) --
</span><span class="comment">*</span><span class="comment"> Univ. of Tennessee, Univ. of California Berkeley and NAG Ltd..
</span><span class="comment">*</span><span class="comment"> November 2006
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> .. Scalar Arguments ..
</span> CHARACTER EIGSRC, INITV, SIDE
INTEGER INFO, LDH, LDVL, LDVR, M, MM, N
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment"> .. Array Arguments ..
</span> LOGICAL SELECT( * )
INTEGER IFAILL( * ), IFAILR( * )
DOUBLE PRECISION H( LDH, * ), VL( LDVL, * ), VR( LDVR, * ),
$ WI( * ), WORK( * ), WR( * )
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> Purpose
</span><span class="comment">*</span><span class="comment"> =======
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> <a name="DHSEIN.23"></a><a href="dhsein.f.html#DHSEIN.1">DHSEIN</a> uses inverse iteration to find specified right and/or left
</span><span class="comment">*</span><span class="comment"> eigenvectors of a real upper Hessenberg matrix H.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> The right eigenvector x and the left eigenvector y of the matrix H
</span><span class="comment">*</span><span class="comment"> corresponding to an eigenvalue w are defined by:
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> H * x = w * x, y**h * H = w * y**h
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> where y**h denotes the conjugate transpose of the vector y.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> Arguments
</span><span class="comment">*</span><span class="comment"> =========
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> SIDE (input) CHARACTER*1
</span><span class="comment">*</span><span class="comment"> = 'R': compute right eigenvectors only;
</span><span class="comment">*</span><span class="comment"> = 'L': compute left eigenvectors only;
</span><span class="comment">*</span><span class="comment"> = 'B': compute both right and left eigenvectors.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> EIGSRC (input) CHARACTER*1
</span><span class="comment">*</span><span class="comment"> Specifies the source of eigenvalues supplied in (WR,WI):
</span><span class="comment">*</span><span class="comment"> = 'Q': the eigenvalues were found using <a name="DHSEQR.43"></a><a href="dhseqr.f.html#DHSEQR.1">DHSEQR</a>; thus, if
</span><span class="comment">*</span><span class="comment"> H has zero subdiagonal elements, and so is
</span><span class="comment">*</span><span class="comment"> block-triangular, then the j-th eigenvalue can be
</span><span class="comment">*</span><span class="comment"> assumed to be an eigenvalue of the block containing
</span><span class="comment">*</span><span class="comment"> the j-th row/column. This property allows <a name="DHSEIN.47"></a><a href="dhsein.f.html#DHSEIN.1">DHSEIN</a> to
</span><span class="comment">*</span><span class="comment"> perform inverse iteration on just one diagonal block.
</span><span class="comment">*</span><span class="comment"> = 'N': no assumptions are made on the correspondence
</span><span class="comment">*</span><span class="comment"> between eigenvalues and diagonal blocks. In this
</span><span class="comment">*</span><span class="comment"> case, <a name="DHSEIN.51"></a><a href="dhsein.f.html#DHSEIN.1">DHSEIN</a> must always perform inverse iteration
</span><span class="comment">*</span><span class="comment"> using the whole matrix H.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> INITV (input) CHARACTER*1
</span><span class="comment">*</span><span class="comment"> = 'N': no initial vectors are supplied;
</span><span class="comment">*</span><span class="comment"> = 'U': user-supplied initial vectors are stored in the arrays
</span><span class="comment">*</span><span class="comment"> VL and/or VR.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> SELECT (input/output) LOGICAL array, dimension (N)
</span><span class="comment">*</span><span class="comment"> Specifies the eigenvectors to be computed. To select the
</span><span class="comment">*</span><span class="comment"> real eigenvector corresponding to a real eigenvalue WR(j),
</span><span class="comment">*</span><span class="comment"> SELECT(j) must be set to .TRUE.. To select the complex
</span><span class="comment">*</span><span class="comment"> eigenvector corresponding to a complex eigenvalue
</span><span class="comment">*</span><span class="comment"> (WR(j),WI(j)), with complex conjugate (WR(j+1),WI(j+1)),
</span><span class="comment">*</span><span class="comment"> either SELECT(j) or SELECT(j+1) or both must be set to
</span><span class="comment">*</span><span class="comment"> .TRUE.; then on exit SELECT(j) is .TRUE. and SELECT(j+1) is
</span><span class="comment">*</span><span class="comment"> .FALSE..
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> N (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The order of the matrix H. N >= 0.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> H (input) DOUBLE PRECISION array, dimension (LDH,N)
</span><span class="comment">*</span><span class="comment"> The upper Hessenberg matrix H.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> LDH (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The leading dimension of the array H. LDH >= max(1,N).
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> WR (input/output) DOUBLE PRECISION array, dimension (N)
</span><span class="comment">*</span><span class="comment"> WI (input) DOUBLE PRECISION array, dimension (N)
</span><span class="comment">*</span><span class="comment"> On entry, the real and imaginary parts of the eigenvalues of
</span><span class="comment">*</span><span class="comment"> H; a complex conjugate pair of eigenvalues must be stored in
</span><span class="comment">*</span><span class="comment"> consecutive elements of WR and WI.
</span><span class="comment">*</span><span class="comment"> On exit, WR may have been altered since close eigenvalues
</span><span class="comment">*</span><span class="comment"> are perturbed slightly in searching for independent
</span><span class="comment">*</span><span class="comment"> eigenvectors.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> VL (input/output) DOUBLE PRECISION array, dimension (LDVL,MM)
</span><span class="comment">*</span><span class="comment"> On entry, if INITV = 'U' and SIDE = 'L' or 'B', VL must
</span><span class="comment">*</span><span class="comment"> contain starting vectors for the inverse iteration for the
</span><span class="comment">*</span><span class="comment"> left eigenvectors; the starting vector for each eigenvector
</span><span class="comment">*</span><span class="comment"> must be in the same column(s) in which the eigenvector will
</span><span class="comment">*</span><span class="comment"> be stored.
</span><span class="comment">*</span><span class="comment"> On exit, if SIDE = 'L' or 'B', the left eigenvectors
</span><span class="comment">*</span><span class="comment"> specified by SELECT will be stored consecutively in the
</span><span class="comment">*</span><span class="comment"> columns of VL, in the same order as their eigenvalues. A
</span><span class="comment">*</span><span class="comment"> complex eigenvector corresponding to a complex eigenvalue is
</span><span class="comment">*</span><span class="comment"> stored in two consecutive columns, the first holding the real
</span><span class="comment">*</span><span class="comment"> part and the second the imaginary part.
</span><span class="comment">*</span><span class="comment"> If SIDE = 'R', VL is not referenced.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> LDVL (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The leading dimension of the array VL.
</span><span class="comment">*</span><span class="comment"> LDVL >= max(1,N) if SIDE = 'L' or 'B'; LDVL >= 1 otherwise.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> VR (input/output) DOUBLE PRECISION array, dimension (LDVR,MM)
</span><span class="comment">*</span><span class="comment"> On entry, if INITV = 'U' and SIDE = 'R' or 'B', VR must
</span><span class="comment">*</span><span class="comment"> contain starting vectors for the inverse iteration for the
</span><span class="comment">*</span><span class="comment"> right eigenvectors; the starting vector for each eigenvector
</span><span class="comment">*</span><span class="comment"> must be in the same column(s) in which the eigenvector will
</span><span class="comment">*</span><span class="comment"> be stored.
</span><span class="comment">*</span><span class="comment"> On exit, if SIDE = 'R' or 'B', the right eigenvectors
</span><span class="comment">*</span><span class="comment"> specified by SELECT will be stored consecutively in the
</span><span class="comment">*</span><span class="comment"> columns of VR, in the same order as their eigenvalues. A
</span><span class="comment">*</span><span class="comment"> complex eigenvector corresponding to a complex eigenvalue is
</span><span class="comment">*</span><span class="comment"> stored in two consecutive columns, the first holding the real
</span><span class="comment">*</span><span class="comment"> part and the second the imaginary part.
</span><span class="comment">*</span><span class="comment"> If SIDE = 'L', VR is not referenced.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> LDVR (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The leading dimension of the array VR.
</span><span class="comment">*</span><span class="comment"> LDVR >= max(1,N) if SIDE = 'R' or 'B'; LDVR >= 1 otherwise.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> MM (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The number of columns in the arrays VL and/or VR. MM >= M.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> M (output) INTEGER
</span><span class="comment">*</span><span class="comment"> The number of columns in the arrays VL and/or VR required to
⌨️ 快捷键说明
复制代码Ctrl + C
搜索代码Ctrl + F
全屏模式F11
增大字号Ctrl + =
减小字号Ctrl + -
显示快捷键?