Hi, was wondering if anyone could help. there are a few things i need to know about some Matlab functions 1- if Pwelch and fft are used to find the Spectral Power Density. but how come when u apply them to the same data, the graphs look different? 2- when using the sendmail function, how does Matlab make the connection and send the data? ive looked at the code that Matlab uses for "sendmail" but its very difficult to understand. if anyone could help, i would be really greatful . thanks.