How to change psd function to Periodogram

Hi there,

I have a code written by psd function and would like to update it using Periodogram/Pwelch. I have tried but I could not find what should be f value as the input parameters. I wonder if you could please help me with that.

Thanks.

function varargout=psd2(varargin)

%PSD2 Power Spectral Density and frequency characteristics.

% PSD2 estimates the power spectral density (PSD), mean power frequency (MPF),

% median power frequency (F50),

% peak frequency (PEAK), and limit frequency (F95) that contains up to 95%

% of the PSD using Welch's averaged periodogram method (PSD Matlab function).

% [MPF,PEAK,F50,F95,F,P]=psd2(X,Fs,NFFT,WINDOW,NOVERLAP,DFLAG)

% [MPF,PEAK,F50,F95,F,P]=psd2(X,Fs) uses default values

% Inputs:

% X: data vector

% Fs: sampling frequency

% NFFT,WINDOW,NOVERLAP,DFLAG: see PSD matlab function for help

% default values: NFFT=1024, WINDOW=256, NOVERLAP=WINDOW/2, DFLAG='mean'

% Outputs:

% MPF: mean power frequency

% PEAK: peak frequency (mode)

% F50: median frequency of the power spectral density

% F95: frequency limit that contains up to 95% of the power spectral density

% F: frequency vector

% P: PSD estimated vector

%

% See also PSD

% Marcos Duarte [e-mail] 11oct1998

% one typo and F50 comment modified slightly by Hyun Gu Kang

if nargin == 2

x=varargin{1};

fs=varargin{2};

if length(x)<1000

nfft=length(x); window=round(nfft/4);

else

nfft=1024; window=nfft/4;

end

noverlap=round(window/2); dflag='mean';

end

if nargin >= 3

if ~isempty(varargin{3})

nfft=varargin{3};

else

if length(x)<1000, nfft=length(x); else nfft=1024; end

end

end

if nargin >= 4

if ~isempty(varargin{4}), window=varargin{4}; else window=round(nfft/4); end

end

if nargin >= 5

if ~isempty(varargin{5}), noverlap=varargin{5}; else noverlap=round(window/2); end

end

if nargin >= 6

if ~isempty(varargin{6}), dflag=varargin{6}; else dflag='mean'; end

end

if nargin==1 | nargin > 6

error('Incorrect number of inputs')

return

end

%power spectral density:

[p,f]=psd(x,length(x),fs,length(x));

%mpf:

mpf=trapz(f,f.*p)/trapz(f,p);

%peak:

[m,peak]=max(p);

peak=f(peak);

%50 and 95% of PSD:

area=cumtrapz(f,p);

f50=find(area >= .50*area(end));

if ~isempty(f50)

f50=f(f50(1));

else

f50=0;

end

f95=find(area >= .95*area(end));

if ~isempty(f95)

f95=f(f95(1));

else

f95=0;

end

varargout{1}=mpf;

varargout{2}=peak;

varargout{3}=f50;

varargout{4}=f95;

varargout{5}=f;

varargout{6}=p;

[Abhishek Kumar]

Dear Hamed, I tried to run your script by replacing psd with pwelch, the code works fine could you please elaborate on what issue you are facing to be able to help you better?