void SmoothFilter::smoothSavGol(double *, double *y)
{
double *s = new double[d_n];
int nl = d_smooth_points;
int nr = d_sav_gol_points;
int np = nl+nr+1;
double *c = vector(1, np);
//seek shift index for given case nl, nr, m (see savgol).
int *index = intvector(1, np);
index[1]=0;
int i, j=3;
for (i=2; i<=nl+1; i++)
{// index(2)=-1; index(3)=-2; index(4)=-3; index(5)=-4; index(6)=-5
index[i]=i-j;
j += 2;
}
j=2;
for (i=nl+2; i<=np; i++)
{// index(7)= 5; index(8)= 4; index(9)= 3; index(10)=2; index(11)=1
index[i]=i-j;
j += 2;
}
//calculate Savitzky-Golay filter coefficients.
savgol(c, np, nl, nr, 0, d_polynom_order);
for (i=0; i<d_n; i++){// Apply filter to input data.
s[i]=0.0;
for (j=1; j<=np; j++){
int it = i+index[j];
if (it >=0 && it < d_n)//skip left points that do not exist.
s[i] += c[j]*y[i+index[j]];
}
}
for (i = 0; i<d_n; i++)
y[i] = s[i];
delete[] s;
free_vector(c, 1, np);
free_intvector(index, 1, np);
}
int main(void)
{
int i,j,m,nl,np,nr;
float *c,sum;
static int mtest[NTEST+1]={0,2,2,2,2,4,4};
static int nltest[NTEST+1]={0,2,3,4,5,4,5};
static int nrtest[NTEST+1]={0,2,1,0,5,4,5};
static char *ans[NTEST+1]={"",
" -0.086 0.343 0.486 0.343 -0.086",
" -0.143 0.171 0.343 0.371 0.257",
" 0.086 -0.143 -0.086 0.257 0.886",
" -0.084 0.021 0.103 0.161 0.196 0.207 0.196 0.161 0.103 0.021 -0.084",
" 0.035 -0.128 0.070 0.315 0.417 0.315 0.070 -0.128 0.035",
" 0.042 -0.105 -0.023 0.140 0.280 0.333 0.280 0.140 -0.023 -0.105 0.042"};
c=vector(1,NMAX);
printf("M nl nr\n");
printf("\t\t\tSample Savitzky-Golay Coefficients\n");
for (i=1;i<=NTEST;i++) {
m=mtest[i];
nl=nltest[i];
nr=nrtest[i];
np=nl+nr+1;
savgol(c,np,nl,nr,0,m);
for (sum=0.0,j=1;j<=np;j++) sum += c[j];
printf("%1d %1d %1d\n",m,nl,nr);
for (j=nl;j<5;j++) printf("%7s"," ");
for (j=nl+1;j>=1;j--) printf("%7.3f",c[j]);
for (j=0;j<nr;j++) printf("%7.3f",c[np-j]);
printf("\n");
printf("Sum = %7.3f\n",sum);
printf("Compare answer:\n%s\n",ans[i]);
}
free_vector(c,1,NMAX);
return 0;
}
