Why do I get unrecognized function for a built in function?

%%
% AM Signal Generation Routine
%
clear
close all

%% 
% Select a test waveform
load train;

% Listen to the test waveform
p1 = audioplayer(y, Fs);
playblocking(p1);

[nrow,ncol]=size(y);

if ncol ==2
    y=sum(y,2);
end

%%
% Set Signal Rates and Constants
Interprate=8;

Fmax=Fs/2;
Fis=Interprate*Fs;
Fc=Fis/4;
mu=0.5;

FFTsize=4096;
FreqAxis=((1:FFTsize)'-1)*Fis/FFTsize;
FreqAxis2=((1:FFTsize)'-1)*Fis/FFTsize - Fis/2;

%Determine the time sample instances
maxtime=length(y)/Fs;

timevect=(0:1/Fis:(maxtime-1/Fis))';
tvlength=length(timevect);

%%
% Increase the sampled data rate prior to modulation
% Built in MATLAB function to increase sample rate
[message,InterpFilter] = interp(y,Interprate);

SpecInterpFilter=fft(InterpFilter/sum(InterpFilter),FFTsize);
BeqnIntF=0.5*(sum(psdg(SpecInterpFilter))/psdg(SpecInterpFilter(1)))*(Fis/FFTsize);

Unrecognized function or variable 'psdg'.

Getting unrecognized function for psdg. Not sure why as this is a built in fucntion.

[chrisw23]

Is the function called psd or really psdg

[Walter Roberson]

There is no Mathworks function by that name.

Answer 1

[John D'Errico]

which psdg -all

'psdg' not found.

As you can see, psdg does not exist as a MATLAB function, in any toolbox we can search, and they are all pretty much accessible from here.

Most likely, psdg is a function that you got from somebody else, or one you should look to from someone else. Here, for example, we see a call with that name, but no code provided.

https://homepages.wmich.edu/~bazuinb/ECE6560/FilterNotes.pdf

But it is not a built-in MATLAB function that I can find. A possibility is this is a typo, that you misspelled the name.