Re: please help signal processing " daptive filter"
If you are using MATLAB along with the Signal Processing Toolbox, then use filtering with the "filtfilt" command. This command performs true "Zero Phase" (i.e. no delay) filtering by using a forward-reverse filtering implementation.
It works with any filter like FIR, IIR, linear phase, etc.
Alternatively, you can pad the data at the ends with intelligently selected values and then take the sections of the filtered output which correspond to your input.