zmachine.c

Meschach 可以解稠密或稀疏线性方程组、计算特征值和特征向量和解最小平方问题

/**************************************************************************
**
** Copyright (C) 1993 David E. Steward & Zbigniew Leyk, all rights reserved.
**
**			     Meschach Library
** 
** This Meschach Library is provided "as is" without any express 
** or implied warranty of any kind with respect to this software. 
** In particular the authors shall not be liable for any direct, 
** indirect, special, incidental or consequential damages arising 
** in any way from use of the software.
** 
** Everyone is granted permission to copy, modify and redistribute this
** Meschach Library, provided:
**  1.  All copies contain this copyright notice.
**  2.  All modified copies shall carry a notice stating who
**      made the last modification and the date of such modification.
**  3.  No charge is made for this software or works derived from it.  
**      This clause shall not be construed as constraining other software
**      distributed on the same medium as this software, nor is a
**      distribution fee considered a charge.
**
***************************************************************************/


/*
  This file contains basic routines which are used by the functions
  involving complex vectors.
  These are the routines that should be modified in order to take
  full advantage of specialised architectures (pipelining, vector
  processors etc).
  */
static	char	*rcsid = "$Id: zmachine.c,v 1.1 1994/01/13 04:25:41 des Exp $";

#include	<math.h>
#include	"machine.h"
#include        "zmatrix.h"


/* __zconj__ -- complex conjugate */
#ifndef ANSI_C
void	__zconj__(zp,len)
complex	*zp;
int	len;
#else
void	__zconj__(complex zp[], int len)
#endif
{
    int		i;

    for ( i = 0; i < len; i++ )
	zp[i].im = - zp[i].im;
}

/* __zip__ -- inner product
	-- computes sum_i zp1[i].zp2[i] if flag == 0
		    sum_i zp1[i]*.zp2[i] if flag != 0 */
#ifndef ANSI_C
complex	__zip__(zp1,zp2,len,flag)
complex	*zp1, *zp2;
int	flag, len;
#else
complex	__zip__(const complex *zp1, const complex *zp2, int len, int flag)
#endif
{
    complex	sum;
    int		i;

    sum.re = sum.im = 0.0;
    if ( flag )
    {
	for ( i = 0; i < len; i++ )
	{
	    sum.re += zp1[i].re*zp2[i].re + zp1[i].im*zp2[i].im;
	    sum.im += zp1[i].re*zp2[i].im - zp1[i].im*zp2[i].re;
	}
    }
    else
    {
	for ( i = 0; i < len; i++ )
	{
	    sum.re += zp1[i].re*zp2[i].re - zp1[i].im*zp2[i].im;
	    sum.im += zp1[i].re*zp2[i].im + zp1[i].im*zp2[i].re;
	}
    }

    return sum;
}

/* __zmltadd__ -- scalar multiply and add i.e. complex saxpy
	-- computes zp1[i] += s.zp2[i]  if flag == 0
	-- computes zp1[i] += s.zp2[i]* if flag != 0 */
#ifndef ANSI_C
void	__zmltadd__(zp1,zp2,s,len,flag)
complex	*zp1, *zp2, s;
int	flag, len;
#else
void	__zmltadd__(complex *zp1, const complex *zp2, complex s,
		    int len, int flag)
#endif
{
    int		i;
    LongReal	t_re, t_im;

    if ( ! flag )
    {
	for ( i = 0; i < len; i++ )
	{
	    t_re = zp1[i].re + s.re*zp2[i].re - s.im*zp2[i].im;
	    t_im = zp1[i].im + s.re*zp2[i].im + s.im*zp2[i].re;
	    zp1[i].re = t_re;
	    zp1[i].im = t_im;
	}
    }
    else
    {
	for ( i = 0; i < len; i++ )
	{
	    t_re = zp1[i].re + s.re*zp2[i].re + s.im*zp2[i].im;
	    t_im = zp1[i].im - s.re*zp2[i].im + s.im*zp2[i].re;
	    zp1[i].re = t_re;
	    zp1[i].im = t_im;
	}
    }
}

/* __zmlt__ scalar complex multiply array c.f. sv_mlt() */
#ifndef ANSI_C
void	__zmlt__(zp,s,out,len)
complex	*zp, s, *out;
register int	len;
#else
void	__zmlt__(const complex *zp, complex s, complex *out, int len)
#endif
{
    int		i;
    LongReal	t_re, t_im;

    for ( i = 0; i < len; i++ )
    {
	t_re = s.re*zp[i].re - s.im*zp[i].im;
	t_im = s.re*zp[i].im + s.im*zp[i].re;
	out[i].re = t_re;
	out[i].im = t_im;
    }
}

/* __zadd__ -- add complex arrays c.f. v_add() */
#ifndef ANSI_C
void	__zadd__(zp1,zp2,out,len)
complex	*zp1, *zp2, *out;
int	len;
#else
void	__zadd__(const complex *zp1, const complex *zp2, complex *out, int len)
#endif
{
    int		i;
    for ( i = 0; i < len; i++ )
    {
	out[i].re = zp1[i].re + zp2[i].re;
	out[i].im = zp1[i].im + zp2[i].im;
    }
}

/* __zsub__ -- subtract complex arrays c.f. v_sub() */
#ifndef ANSI_C
void	__zsub__(zp1,zp2,out,len)
complex	*zp1, *zp2, *out;
int	len;
#else
void	__zsub__(const complex *zp1, const complex *zp2, complex *out, int len)
#endif
{
    int		i;
    for ( i = 0; i < len; i++ )
    {
	out[i].re = zp1[i].re - zp2[i].re;
	out[i].im = zp1[i].im - zp2[i].im;
    }
}

/* __zzero__ -- zeros an array of complex numbers */
#ifndef ANSI_C
void	__zzero__(zp,len)
complex	*zp;
int	len;
#else
void	__zzero__(complex *zp, int len)
#endif
{
    /* if a Real precision zero is equivalent to a string of nulls */
    MEM_ZERO((char *)zp,len*sizeof(complex));
    /* else, need to zero the array entry by entry */
    /******************************
    while ( len-- )
    {
	zp->re = zp->im = 0.0;
	zp++;
    }
    ******************************/
}