problem with a line

hello maybe somebody can explain me this line? [Pxx,W] = pwelch(st,[],[],4096,20);

and what is the inverse command for 'pwelch'? thank u very much!

Answer 1

[Ivan van der Kroon]

Just type

doc pwelch

and everything you need is there. If I remember correctly a power spectrum discards the phase information so it is not irreversible.