zrotg.f.html

来自「famous linear algebra library (LAPACK) p」· HTML 代码 · 共 57 行

HTML
57
字号
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
 <head>
  <title>zrotg.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.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="ZROTG.1"></a><a href="zrotg.f.html#ZROTG.1">ZROTG</a>(CA,CB,C,S)
<span class="comment">*</span><span class="comment">     .. Scalar Arguments ..
</span>      DOUBLE COMPLEX CA,CB,S
      DOUBLE PRECISION C
<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">     determines a double complex Givens rotation.
</span><span class="comment">*</span><span class="comment">
</span><span class="comment">*</span><span class="comment">     .. Local Scalars ..
</span>      DOUBLE COMPLEX ALPHA
      DOUBLE PRECISION NORM,SCALE
<span class="comment">*</span><span class="comment">     ..
</span><span class="comment">*</span><span class="comment">     .. Intrinsic Functions ..
</span>      INTRINSIC CDABS,DCMPLX,DCONJG,DSQRT
<span class="comment">*</span><span class="comment">     ..
</span>      IF (CDABS(CA).NE.0.0d0) GO TO 10
      C = 0.0d0
      S = (1.0d0,0.0d0)
      CA = CB
      GO TO 20
   10 CONTINUE
      SCALE = CDABS(CA) + CDABS(CB)
      NORM = SCALE*DSQRT((CDABS(CA/DCMPLX(SCALE,0.0d0)))**2+
     +       (CDABS(CB/DCMPLX(SCALE,0.0d0)))**2)
      ALPHA = CA/CDABS(CA)
      C = CDABS(CA)/NORM
      S = ALPHA*DCONJG(CB)/NORM
      CA = ALPHA*NORM
   20 CONTINUE
      RETURN
      END

</pre>

 </body>
</html>

⌨️ 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?