What do these lines mean?

Hi there, I want to know what do these two lines mean :

[q,v] = max(10*log10(p));

And

[s,f,t,p] = spectrogram(y,100,80,100,Fs);

Answer 1

[Walter Roberson]

p is a vector or an array. log10(p) is logarithm base 10. Multiply that by 10. If the result is a vector, return the maximum value of the vector into q and return the location the maximum value was found at in v. If the result is an array, return the maximum value of each column into q and return the location of the maximum value in each column in v.

10*log10(x) is often used to calculate decibels.

Equivalent code would be

[maxp, v] = max(p);
q = 10*log10(maxp);

[Mohamed Nedal]

@Walter Robertson: Thank you very much for your answer. I have a couple of questions please :

1. You said that if the result is an array, return the maximum value of each column into q and return the location of the maximum value in each column in v. DO you mean return the location of the maximum value in each "row" in v or in each "colum" ?

2. What about the command line ?

[s,f,t,p] = spectrogram(y,100,80,100,Fs);

[Walter Roberson]

If you do not specify the dimension to work along and p is a 2D array, then [maxp, v] = max(p) would be equivalent to

for K = 1 : size(p,2)
  [maxp(1,K), v(1,K)] = max(p(:,K));
end

That is, the maximum in each column.

I am not familiar with spectrogram() and I have to cut my lawn so I do not choose to study the topic at this time.