/*______________________________________________________________________
BHWTBL.C  Blackman-Harris Window Table Generator

Author: 24-APR-91, Ronnin Yee, Analog Devices DSP Div. (617) 461-3672
______________________________________________________________________*/

#include <stdio.h>
#include <math.h>
#define MAX_LEN 16384
main()
{
  int i, n, iter;
  double    freq, c,
            a0=0.42659,
            a1=0.49656,
            a2=0.076848;
  double    pi=3.14159265359;
  FILE *c_file;
  char filename1[25];

  printf("%c%c%c%c",27,91,50,74); /*clear screen*/
  printf("%c%c%c",27,91,72);      /*curser home*/
  printf("________________Blackman-Harris Window Table Generator____________\n");
  printf("Generates Blackman-Harris Window coefficients for the 21k-ezlab demo\n");
  printf("program.\n");
  printf("24-APR-91, Ronnin Yee, Analog Devices\n");
  printf("_____________________________________________________________\n");

  printf("Enter the number of points (max %d) -> ",MAX_LEN);
  scanf(" %d",&n);
  iter=n/2;

  printf("\n  Enter Blackman-Harris coeff table filename: ");
  scanf(" %s",filename1);
  c_file=fopen(filename1,"w");

  freq=2.0*pi/(double)n;
  for (i=0; i <= iter; i++)
  {
    c=a0+a1*cos((double)i * freq)+a2*cos(2.0*(double)i * freq);
    fprintf(c_file,"%22.14e\n",c);
    printf("%d : %22.14e\r",i,c);
  }
  fclose(c_file);

  printf("\n\nFinished\n\n");
}