convolut.c

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#include "tpcclibConfig.h"
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#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <time.h>
#include <string.h>
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#include "tpccm.h"
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int convolve1D(
  double *data,
  const int n,
  double *kernel,
  const int m,
  double *out
) {
  if(n<1 || m<1 || data==NULL || kernel==NULL || out==NULL || out==data) return(1);
 
  for(int di=0; di<n; di++) out[di]=0.0;
 
  for(int di=m-1; di<n; di++) {
    int dj=di;
    for(int k=0; k<m; k++)
      out[di] += data[dj--] * kernel[k];
  }
 
  for(int di=0; di<n && di<m-1; di++) {
    int k=0;
    for(int dj=di; dj>=0; dj--)
      out[di] += data[dj] * kernel[k++];
  }
 
  return(0);
}
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int simIsSteadyInterval(
  double *x,
  const int n,
  double *f
) {
  if(f!=NULL) *f=nan("");
  if(x==NULL || n<2) return(0);
  //if(!(fabs(x[0])>1.0E-12)) return(0); // on purpose, to catch NaN
 
  double d, freq=nan("");
  int isdif=0;
  for(int i=1; i<n; i++) {
    d=x[i]-x[i-1];
    if(!(d>1.0E-12)) return(0); // interval must be > 0
    if(isnan(freq)) {freq=d; continue;} // first interval
    if(fabs(freq-d)<1.0E-12) continue; // same interval as before
    isdif++; // different
    if(d<freq) freq=d; // save smaller interval
  }
  if(f!=NULL) *f=freq;
  if(isdif>0) return(0); // variable intervals
  /* Check that first sample time is at the midpoint of interval starting from 0 */
  d=0.5*freq; //printf("d=%g x[0]=%g\n", d, x[0]);
  if(fabs(x[0]-d)>1.0E-06) return(0);
  return(1);
}
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