xinit('spect.2.ps')
//test modified periodogram method
//and correlation method spectral estimation techniques

   
   dess(31)=1;

//generate white data

   rand('normal');
   rand('seed',0);
   x=rand(1:1024-33+1);

//make low-pass filter with eqfir
   
   nf=33;
   bedge=[0 .1;.125 .5];
   des=[1 0];
   wate=[1 1];
   h=eqfir(nf,bedge,des,wate);

//filter white data to obtain colored data 

   h1=[h 0*ones(1:maxi(size(x))-1)];
   x1=[x 0*ones(1:maxi(size(h))-1)];
   hf=fft(h1,-1);
   xf=fft(x1,-1);
   yf=hf.*xf;
   y=real(fft(yf,1));

//plot magnitude of filter

   h2=[h 0*ones(1:968)];   
   hf2=fft(h2,-1);
   hf2=real(hf2.*conj(hf2));
   hsize=maxi(size(hf2));
   fr=(1:hsize)/hsize;
   plot(fr,log(hf2));
   xend()
xinit('spect.3.ps')
//pspect example

   [sm]=pspect(100,200,'tr',y);
   smsize=maxi(size(sm));
   fr=(1:smsize)/smsize;
   plot(fr,log(sm))
   
   xend(),
xinit('spect.4.ps')
//cspect example

   [sm]=cspect(100,200,'tr',y);
   smsize=maxi(size(sm));
   fr=(1:smsize)/smsize;
   plot(fr,log(sm))
   
   xend()

