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2025-02-Numerical/lib/nr/cpp/recipes/period.cpp
2025-09-12 18:55:25 +09:00

71 lines
1.6 KiB
C++

#include <cmath>
#include "nr.h"
using namespace std;
void NR::period(Vec_I_DP &x, Vec_I_DP &y, const DP ofac, const DP hifac,
Vec_O_DP &px, Vec_O_DP &py, int &nout, int &jmax, DP &prob)
{
const DP TWOPI=6.283185307179586476;
int i,j;
DP ave,c,cc,cwtau,effm,expy,pnow,pymax,s,ss,sumc,sumcy,sums,sumsh,
sumsy,swtau,var,wtau,xave,xdif,xmax,xmin,yy,arg,wtemp;
int n=x.size();
int np=px.size();
Vec_DP wi(n),wpi(n),wpr(n),wr(n);
nout=0.5*ofac*hifac*n;
if (nout > np) nrerror("output arrays too short in period");
avevar(y,ave,var);
if (var == 0.0) nrerror("zero variance in period");
xmax=xmin=x[0];
for (j=0;j<n;j++) {
if (x[j] > xmax) xmax=x[j];
if (x[j] < xmin) xmin=x[j];
}
xdif=xmax-xmin;
xave=0.5*(xmax+xmin);
pymax=0.0;
pnow=1.0/(xdif*ofac);
for (j=0;j<n;j++) {
arg=TWOPI*((x[j]-xave)*pnow);
wpr[j]= -2.0*SQR(sin(0.5*arg));
wpi[j]=sin(arg);
wr[j]=cos(arg);
wi[j]=wpi[j];
}
for (i=0;i<nout;i++) {
px[i]=pnow;
sumsh=sumc=0.0;
for (j=0;j<n;j++) {
c=wr[j];
s=wi[j];
sumsh += s*c;
sumc += (c-s)*(c+s);
}
wtau=0.5*atan2(2.0*sumsh,sumc);
swtau=sin(wtau);
cwtau=cos(wtau);
sums=sumc=sumsy=sumcy=0.0;
for (j=0;j<n;j++) {
s=wi[j];
c=wr[j];
ss=s*cwtau-c*swtau;
cc=c*cwtau+s*swtau;
sums += ss*ss;
sumc += cc*cc;
yy=y[j]-ave;
sumsy += yy*ss;
sumcy += yy*cc;
wr[j]=((wtemp=wr[j])*wpr[j]-wi[j]*wpi[j])+wr[j];
wi[j]=(wi[j]*wpr[j]+wtemp*wpi[j])+wi[j];
}
py[i]=0.5*(sumcy*sumcy/sumc+sumsy*sumsy/sums)/var;
if (py[i] >= pymax) pymax=py[jmax=i];
pnow += 1.0/(ofac*xdif);
}
expy=exp(-pymax);
effm=2.0*nout/ofac;
prob=effm*expy;
if (prob > 0.01) prob=1.0-pow(1.0-expy,effm);
}