I have raw data in following format Time <-> Ch1 <-> Ch2 <-> Ch3 0.01 <-> 1.6 <-> 1.62 <-> 1.92 0.03 <-> 1.63 <-> 1.62 <-> 1.96 0.05 <-> 1.63 <-> 1.63 <-> 2.04 ..........so on 1000 raw PS: those <-> are used in this forum to show as table, in actual data those are separate column. How can I plot FFT in matlab from this data ? Do I have to convert anything first ? I am newbi to matlab, any help would be greatly appreciated. Thanks a lot in advance.