zlagtm.f.html

来自「famous linear algebra library (LAPACK) p」· HTML 代码 · 共 258 行 · 第 1/2 页

HTML
258 行
字号
12
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
 <head>
  <title>zlagtm.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="ZLAGTM.1"></a><a href="zlagtm.f.html#ZLAGTM.1">ZLAGTM</a>( TRANS, N, NRHS, ALPHA, DL, D, DU, X, LDX, BETA,
     $                   B, LDB )
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  -- LAPACK auxiliary 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          TRANS
      INTEGER            LDB, LDX, N, NRHS
      DOUBLE PRECISION   ALPHA, BETA
<span class="comment">*</span><span class="comment">     ..
</span><span class="comment">*</span><span class="comment">     .. Array Arguments ..
</span>      COMPLEX*16         B( LDB, * ), D( * ), DL( * ), DU( * ),
     $                   X( LDX, * )
<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="ZLAGTM.21"></a><a href="zlagtm.f.html#ZLAGTM.1">ZLAGTM</a> performs a matrix-vector product of the form
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">     B := alpha * A * X + beta * B
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  where A is a tridiagonal matrix of order N, B and X are N by NRHS
</span><span class="comment">*</span><span class="comment">  matrices, and alpha and beta are real scalars, each of which may be
</span><span class="comment">*</span><span class="comment">  0., 1., or -1.
</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">  TRANS   (input) CHARACTER*1
</span><span class="comment">*</span><span class="comment">          Specifies the operation applied to A.
</span><span class="comment">*</span><span class="comment">          = 'N':  No transpose, B := alpha * A * X + beta * B
</span><span class="comment">*</span><span class="comment">          = 'T':  Transpose,    B := alpha * A**T * X + beta * B
</span><span class="comment">*</span><span class="comment">          = 'C':  Conjugate transpose, B := alpha * A**H * X + beta * B
</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 A.  N &gt;= 0.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  NRHS    (input) INTEGER
</span><span class="comment">*</span><span class="comment">          The number of right hand sides, i.e., the number of columns
</span><span class="comment">*</span><span class="comment">          of the matrices X and B.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  ALPHA   (input) DOUBLE PRECISION
</span><span class="comment">*</span><span class="comment">          The scalar alpha.  ALPHA must be 0., 1., or -1.; otherwise,
</span><span class="comment">*</span><span class="comment">          it is assumed to be 0.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  DL      (input) COMPLEX*16 array, dimension (N-1)
</span><span class="comment">*</span><span class="comment">          The (n-1) sub-diagonal elements of T.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  D       (input) COMPLEX*16 array, dimension (N)
</span><span class="comment">*</span><span class="comment">          The diagonal elements of T.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  DU      (input) COMPLEX*16 array, dimension (N-1)
</span><span class="comment">*</span><span class="comment">          The (n-1) super-diagonal elements of T.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  X       (input) COMPLEX*16 array, dimension (LDX,NRHS)
</span><span class="comment">*</span><span class="comment">          The N by NRHS matrix X.
</span><span class="comment">*</span><span class="comment">  LDX     (input) INTEGER
</span><span class="comment">*</span><span class="comment">          The leading dimension of the array X.  LDX &gt;= max(N,1).
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  BETA    (input) DOUBLE PRECISION
</span><span class="comment">*</span><span class="comment">          The scalar beta.  BETA must be 0., 1., or -1.; otherwise,
</span><span class="comment">*</span><span class="comment">          it is assumed to be 1.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  B       (input/output) COMPLEX*16 array, dimension (LDB,NRHS)
</span><span class="comment">*</span><span class="comment">          On entry, the N by NRHS matrix B.
</span><span class="comment">*</span><span class="comment">          On exit, B is overwritten by the matrix expression
</span><span class="comment">*</span><span class="comment">          B := alpha * A * X + beta * B.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">  LDB     (input) INTEGER
</span><span class="comment">*</span><span class="comment">          The leading dimension of the array B.  LDB &gt;= max(N,1).
</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>      DOUBLE PRECISION   ONE, ZERO
      PARAMETER          ( ONE = 1.0D+0, ZERO = 0.0D+0 )
<span class="comment">*</span><span class="comment">     ..
</span><span class="comment">*</span><span class="comment">     .. Local Scalars ..
</span>      INTEGER            I, J
<span class="comment">*</span><span class="comment">     ..
</span><span class="comment">*</span><span class="comment">     .. External Functions ..
</span>      LOGICAL            <a name="LSAME.85"></a><a href="lsame.f.html#LSAME.1">LSAME</a>
      EXTERNAL           <a name="LSAME.86"></a><a href="lsame.f.html#LSAME.1">LSAME</a>
<span class="comment">*</span><span class="comment">     ..
</span><span class="comment">*</span><span class="comment">     .. Intrinsic Functions ..
</span>      INTRINSIC          DCONJG
<span class="comment">*</span><span class="comment">     ..
</span><span class="comment">*</span><span class="comment">     .. Executable Statements ..
</span><span class="comment">*</span><span class="comment">
</span>      IF( N.EQ.0 )
     $   RETURN
<span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">     Multiply B by BETA if BETA.NE.1.
</span><span class="comment">*</span><span class="comment">
</span>      IF( BETA.EQ.ZERO ) THEN
         DO 20 J = 1, NRHS
            DO 10 I = 1, N
               B( I, J ) = ZERO
   10       CONTINUE
   20    CONTINUE
      ELSE IF( BETA.EQ.-ONE ) THEN
         DO 40 J = 1, NRHS
            DO 30 I = 1, N
               B( I, J ) = -B( I, J )
   30       CONTINUE
   40    CONTINUE
      END IF
12

zlagtm.f.html - 源码说明

本页面展示了「famous linear algebra library (LAPACK) ports to windows」中的 zlagtm.f.html 源码文件，采用 HTML 编程语言编写，共 258 行代码。您可以在线阅读完整代码内容，也可以返回资源详情页下载完整源码包进行本地学习和开发。

虫虫下载站收录了大量与algebra相关的技术资源，包括源代码、技术文档、电路图等，是电子工程师和嵌入式开发者的专业学习平台。

⌨️ 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?