slaeda.f.html
来自「famous linear algebra library (LAPACK) p」· HTML 代码 · 共 242 行 · 第 1/2 页
HTML
242 行
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>slaeda.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="SLAEDA.1"></a><a href="slaeda.f.html#SLAEDA.1">SLAEDA</a>( N, TLVLS, CURLVL, CURPBM, PRMPTR, PERM, GIVPTR,
$ GIVCOL, GIVNUM, Q, QPTR, Z, ZTEMP, 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> INTEGER CURLVL, CURPBM, INFO, N, TLVLS
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment"> .. Array Arguments ..
</span> INTEGER GIVCOL( 2, * ), GIVPTR( * ), PERM( * ),
$ PRMPTR( * ), QPTR( * )
REAL GIVNUM( 2, * ), Q( * ), Z( * ), ZTEMP( * )
<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="SLAEDA.20"></a><a href="slaeda.f.html#SLAEDA.1">SLAEDA</a> computes the Z vector corresponding to the merge step in the
</span><span class="comment">*</span><span class="comment"> CURLVLth step of the merge process with TLVLS steps for the CURPBMth
</span><span class="comment">*</span><span class="comment"> problem.
</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"> N (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The dimension of the symmetric tridiagonal matrix. N >= 0.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> TLVLS (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The total number of merging levels in the overall divide and
</span><span class="comment">*</span><span class="comment"> conquer tree.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> CURLVL (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The current level in the overall merge routine,
</span><span class="comment">*</span><span class="comment"> 0 <= curlvl <= tlvls.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> CURPBM (input) INTEGER
</span><span class="comment">*</span><span class="comment"> The current problem in the current level in the overall
</span><span class="comment">*</span><span class="comment"> merge routine (counting from upper left to lower right).
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> PRMPTR (input) INTEGER array, dimension (N lg N)
</span><span class="comment">*</span><span class="comment"> Contains a list of pointers which indicate where in PERM a
</span><span class="comment">*</span><span class="comment"> level's permutation is stored. PRMPTR(i+1) - PRMPTR(i)
</span><span class="comment">*</span><span class="comment"> indicates the size of the permutation and incidentally the
</span><span class="comment">*</span><span class="comment"> size of the full, non-deflated problem.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> PERM (input) INTEGER array, dimension (N lg N)
</span><span class="comment">*</span><span class="comment"> Contains the permutations (from deflation and sorting) to be
</span><span class="comment">*</span><span class="comment"> applied to each eigenblock.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> GIVPTR (input) INTEGER array, dimension (N lg N)
</span><span class="comment">*</span><span class="comment"> Contains a list of pointers which indicate where in GIVCOL a
</span><span class="comment">*</span><span class="comment"> level's Givens rotations are stored. GIVPTR(i+1) - GIVPTR(i)
</span><span class="comment">*</span><span class="comment"> indicates the number of Givens rotations.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> GIVCOL (input) INTEGER array, dimension (2, N lg N)
</span><span class="comment">*</span><span class="comment"> Each pair of numbers indicates a pair of columns to take place
</span><span class="comment">*</span><span class="comment"> in a Givens rotation.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> GIVNUM (input) REAL array, dimension (2, N lg N)
</span><span class="comment">*</span><span class="comment"> Each number indicates the S value to be used in the
</span><span class="comment">*</span><span class="comment"> corresponding Givens rotation.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> Q (input) REAL array, dimension (N**2)
</span><span class="comment">*</span><span class="comment"> Contains the square eigenblocks from previous levels, the
</span><span class="comment">*</span><span class="comment"> starting positions for blocks are given by QPTR.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> QPTR (input) INTEGER array, dimension (N+2)
</span><span class="comment">*</span><span class="comment"> Contains a list of pointers which indicate where in Q an
</span><span class="comment">*</span><span class="comment"> eigenblock is stored. SQRT( QPTR(i+1) - QPTR(i) ) indicates
</span><span class="comment">*</span><span class="comment"> the size of the block.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> Z (output) REAL array, dimension (N)
</span><span class="comment">*</span><span class="comment"> On output this vector contains the updating vector (the last
</span><span class="comment">*</span><span class="comment"> row of the first sub-eigenvector matrix and the first row of
</span><span class="comment">*</span><span class="comment"> the second sub-eigenvector matrix).
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> ZTEMP (workspace) REAL array, dimension (N)
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> INFO (output) INTEGER
</span><span class="comment">*</span><span class="comment"> = 0: successful exit.
</span><span class="comment">*</span><span class="comment"> < 0: if INFO = -i, the i-th argument had an illegal value.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> Further Details
</span><span class="comment">*</span><span class="comment"> ===============
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> Based on contributions by
</span><span class="comment">*</span><span class="comment"> Jeff Rutter, Computer Science Division, University of California
</span><span class="comment">*</span><span class="comment"> at Berkeley, USA
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> =====================================================================
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment"> .. Parameters ..
</span> REAL ZERO, HALF, ONE
PARAMETER ( ZERO = 0.0E0, HALF = 0.5E0, ONE = 1.0E0 )
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment"> .. Local Scalars ..
</span> INTEGER BSIZ1, BSIZ2, CURR, I, K, MID, PSIZ1, PSIZ2,
$ PTR, ZPTR1
<span class="comment">*</span><span class="comment"> ..
</span><span class="comment">*</span><span class="comment"> .. External Subroutines ..
⌨️ 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?