spplot.c

这是一个数字信号处理的函数库,包括FFT变换各种滤波算法如果你要编写数字信号处理相关的程序这是个不错的选择

#include <stdio.h>

/**********************************************************************/
/*                             SPPLOT                                 */
/*       Plot File Routines for SIGNAL PROCESSING ALGORITHMS.         */
/**********************************************************************/

/* LATEST DATE:  07/06/92. */
/* CREATES THE XY PLOT FILE "NAME.DAT" FOR SUBSEQUENT PLOTTING. */
/* INPUTS:  X(0:N-1)    = ABSCISSA VALUES X(0) THRU X(N-1). */
/*          Y(0:N-1,NP) = ORDINATE VALUES Y(0) THRU Y(N-1) FOR NP CURVES. */
/*          N           = NUMBER OF (X,Y) POINTS ON EACH CURVE. */
/*          NP          = NUMBER OF SEPARATE CURVES, FROM 1 THRU 6. */
/*          NAME        = NAME OF FILE -- 6 CHARACTERS. */
/* THE KTH RECORD OF THE "NAME.DAT" FILE HAS FORMAT (NP+1)2E15.7, AND */
/* CONTENTS X(K),Y(K,1),Y(K,2),...,Y(K,NP).  THUS, WITH NP=1, THE FILE */
/* HAS JUST ONE (X,Y) PAIR PER RECORD. */

#ifndef KR
void pfile1(float *x, float *y, long *number_points, long *number_plots, char *name)
#else
void pfile1(x, y, number_points, number_plots, name)
char *name;
long *number_plots, *number_points;
float *x, *y;
#endif
{
    /* Local variables */
    FILE *fp;
    char filename[11];
    long i, j;

    sprintf(filename,"%s.DAT",name);

    fp = fopen(filename,"w+");

    fprintf(fp, "%6ld%6ld\n", *number_points, *number_plots);
    for ( i = 0 ; i < *number_points ; i++ )
    {
      fprintf(fp,"%15.7E",x[i]);
      for ( j = *number_plots-1 ; j >= 0 ; j-- )
      {
        fprintf(fp,"%15.7E",y[i + (j * *number_points)]);
      }
      fprintf(fp,"\n");
    }
    fclose(fp);

} /* pfile1 */

/* LATEST DATE: 06/30/92 */
/* CREATES THE XY PLOT FILE "NAME.DAT" FOR SUBSEQUENT PLOTTING. */
/* INPUTS:  X0          = STARTING ABSCISSA VALUE, X(0) */
/*          DX          = X INCREMENT, X(K)-X(K-1) */
/*          Y(0:N-1,NP) = ORDINATE VALUES Y(0) THRU Y(N-1) FOR NP CURVES. */
/*          N           = NUMBER OF (X,Y) POINTS ON EACH CURVE. */
/*          NP          = NUMBER OF SEPARATE CURVES, FROM 1 THRU 6. */
/*          NAME        = NAME OF FILE -- 6 CHARACTERS. */
/* THE KTH RECORD OF THE "NAME.DAT" FILE HAS FORMAT (NP+1)2E15.7, AND */
/* CONTENTS X(K),Y(K,1),Y(K,2),...,Y(K,NP).  THUS, WITH NP=1, THE FILE */
/* HAS JUST ONE (X,Y) PAIR PER RECORD. */

#ifndef KR
void pfile2(float *x0, float *dx, float *y, long *number_points, long *number_plots, char *name)
#else
void pfile2(x0, dx, y, number_points, number_plots, name)
char *name;
long *number_points, *number_plots;
float *x0, *dx, *y;
#endif
{
    /* Local variables */
    FILE *fp;
    char filename[11];
    long i, j;

    sprintf(filename,"%s.DAT",name);

    fp = fopen(filename,"w+");

    fprintf(fp, "%6ld%6ld \n", *number_points, *number_plots);
    for ( i = 0 ; i < *number_points ; i++ )
    {
      fprintf(fp,"%15.7E", (*x0 + (i * *dx)));
      for ( j = *number_plots-1 ; j >= 0 ; j-- )
      {
        fprintf(fp,"%15.7E", y[i + (j * *number_points)]);
      }
      fprintf(fp,"\n");
    }
    fclose(fp);

} /* pfile2 */