Matlab: How to get the PSD of a signal?

[janor]

I'm trying to plot the PSD of a signal, I did it using the fft function but I was wondering if there is another direct method?

 

[n.karthick]

Which version of MATLAB you are using? i am using MATLAB 7.8 R2009a. In my version I have a function called 'dspdata.psd' in signal processing toolbox to find psd of input data.

 

[janor]

yes but I have to use fft first, I meant a command like "spectrum" but without windowing, just takes the signal and outputs the psd.