spectr.m

简单的spectra分析程序

clear all;
filename='92hz-600mVrms-0hz.txt'; 
filename2='92hz-600mVrms-0hz-spl.dat';
t_file=fopen(filename);				
td=fscanf(t_file,'%f %f %f %f %f',[5 inf]);
fclose(t_file);
m1=td(1,:);                            
m2=td(2,:);   
x1=td(3,:);                            
x2=td(4,:);   
v1=td(5,:);                            
 
scalm1=3.52;
scalm2=3.31;
m1=m1.*scalm1;
m2=m2.*scalm2;
  %Np=length(h)									  %total number of the input data points
  Nft=65536;  
  dt=1.0/6000.0;                            %sampling interval
   fs=1/dt;                                 %sampling frequency
   df=fs/Nft;                                %frequency interval
   f=df*(1:Nft);                             %frequency sequence
	H=fft(m1,Nft);
   PH=H.*conj(H)/Nft;
 %  Phh=smooth(PH);
Am= 20*log10(PH)+40;
    Amm=smooth(Am);
    

   figure(2)
    plot(f,Am,'r'),Xlabel('U(m/s)','FontSize', 14),Ylabel('SPL(dB)');
    xlim([0 600]);
    hold on
      plot(f,Amm,'b'),Xlabel('U(m/s)','FontSize', 14),Ylabel('SPL(dB)');

   out2(f,Am,filename2);