Try to average several (100, 200, etc.) process statistical indipendent. (to do that you have to put in a loop your actual code and sum the temporary resulting vector in a final vector; then divide the result for the number of iteration present in the loop). The results will be always more smooth increasing the number of iterations (100, 200, ecc) bye 2005/11/4, khmaies@khma... <khmaies@khma...>: > Dear All, > > I am really strugling to write a nice program giving me the curve of the PSD of a random data. If I use the FFT function I will get a descreat representation and not smooth and continues like I found in some publication. Could any one help me with some matlab code to plot a continues PSD. > Thanks very much > regards \

You need to use the parametric methods of power spectral density estimation. There are several methods : Autocorrelation method, Burg Method, Covariance method etc to name some. You can find the help on these methods in the book of Steven M.Kay titled "Modern Spectral Estimation" or in "Digital Signal Processing" by Proakis and Manolakis. The MATLAB functions which implement these methods are : Autocorrelation Method : pyulear Burg Method : pburg Covariance method : pcov These functions give satisfactory results for what is your requirement, smooth curves with good spectral resolution. Use the MATLAB help for the above methods for their usage. These functions directly give PSD's. Hope this helps. Nishit Jain --- khmaies@khma... wrote: > Dear All, > > I am really strugling to write a nice program giving me the curve of > the PSD of a random data. If I use the FFT function I will get a > descreat representation and not smooth and continues like I found in > some publication. Could any one help me with some matlab code to plot > a continues PSD. > Thanks very much > regards > > > ------------------------ Yahoo! Groups Sponsor > --------------------~--> > Get fast access to your favorite Yahoo! Groups. Make Yahoo! your home > page > http://us.click.yahoo.com/dpRU5A/wUILAA/yQLSAA/wHYolB/TM > --------------------------------~-> > Nishit Jain M.Tech IIT Guwahati Great minds have purposes, little minds have wishes.

Hi, Use psd function from MATLAB. If you are using MATLAB version7, use p.welch function. Good Luck! On 11/4/05, khmaies@khma... <khmaies@khma...> wrote: > > Dear All, > > I am really strugling to write a nice program giving me the curve of the > PSD of a random data. If I use the FFT function I will get a descreat > representation and not smooth and continues like I found in some > publication. Could any one help me with some matlab code to plot a continues > PSD. > Thanks very much > regards >

Dear All, I am really strugling to write a nice program giving me the curve of the PSD of a random data. If I use the FFT function I will get a descreat representation and not smooth and continues like I found in some publication. Could any one help me with some matlab code to plot a continues PSD. Thanks very much regards