tfft.m

matlab自编整数次傅立叶分解及波形评估

bk1=data;
f1=200;
%f1=8000/60;
xiuu=2*pi*f1;
bk1(:,1)=bk1(:,1)*xiuu;
temp=0;bm1=0;sz=size(bk1);
factor=data(sz(1),1)*f1;
for i=1:sz(1)-1
    temp=temp+bk1(i,2)*(cos(bk1(i+1,1))-cos(bk1(i,1)));
end
bm1=-1*temp/(pi*factor);
ciuu=10;  %*************************************************

bmm(ciuu)=0;bmm(1)=bm1;

for i=2:ciuu
   bkk=data;
   %alpha=bkk(1,1);
   %bkk(:,1)=bkk(:,1)-alpha;
   
   factor=data(sz(1),1)*f1*i;
   xiuu=2*pi*f1*i;
   bkk(:,1)=bkk(:,1)*xiuu;
   temp=0;
    for j=1:sz(1)-1
       temp=temp+bkk(j,2)*(cos(bkk(j+1,1))-cos(bkk(j,1)));
    end   
    
    bmm(i)=-1*temp/(pi*factor);
    
end

bmm=bmm';

wt=0:0.01:pi*2*data(sz(1),1)*f1;
bz=0*sin(wt);
for i=1:ciuu
  bz=bz+bmm(i)*sin(wt*i); 
 
end
temp=0;
for i=2:ciuu
       temp=temp+bmm(i)^2;
end
THD=sqrt(temp)/abs(bmm(1))*100

inc=1:ciuu;

subplot(2,1,1),plot(bk1(:,1),bk1(:,2),'b',wt,bz,'g',wt,bmm(1)*sin(wt),'r');
%%axis([0,6.3,-1.1,1.1]);
subplot(2,1,2),plot(inc,abs(bmm(inc)),'r.-');
%axis([0,ciuu,0,1]);

grid on

rmstemp=0;
for i=1:ciuu
rmstemp= rmstemp+0.5*(bmm(i))^2;
end
rms=sqrt(rmstemp)