# How to perform FFT on stored digital data [closed]

I have to do FFT in MATLAB on the digital sinusoidal data that is stored in excel. please find the amplitude values of the sine wave discrete signal stored in the Lookup table.

Number of points : 256

Maximum amplitude : 1024

Numbers per row: 1

Numbers are in decimal

512, 525, 537, 550, 562, 575, 587, 600, 612, 624, 636, 649, 661, 673, 684, 696, 708, 719, 731, 742, 753, 764, 775, 786, 796, 807, 817, 827, 837, 846, 856, 865, 874, 883, 891, 900, 908, 916, 923, 931, 938, 945, 951, 957, 964, 969, 975, 980, 985, 990, 994, 998, 1002, 1005, 1009, 1012, 1014, 1016, 1018, 1020, 1022, 1023, 1023, 1024, 1024, 1024, 1023, 1023, 1022, 1020, 1018, 1016, 1014, 1012, 1009, 1005, 1002, 998, 994, 990, 985, 980, 975, 969, 964, 957, 951, 945, 938, 931, 923, 916, 908, 900, 891, 883, 874, 865, 856, 846, 837, 827, 817, 807, 796, 786, 775, 764, 753, 742, 731, 719, 708, 696, 684, 673, 661, 649, 636, 624, 612, 600, 587, 575, 562, 550, 537, 525, 512, 499, 487, 474, 462, 449, 437, 424, 412, 400, 388, 375, 363, 351, 340, 328, 316, 305, 293, 282, 271, 260, 249, 238, 228, 217, 207, 197, 187, 178, 168, 159, 150, 141, 133, 124, 116, 108, 101, 93, 86, 79, 73, 67, 60, 55, 49, 44, 39, 34, 30, 26, 22, 19, 15, 12, 10, 8, 6, 4, 2, 1, 1, 0, 0, 0, 1, 1, 2, 4, 6, 8, 10, 12, 15, 19, 22, 26, 30, 34, 39, 44, 49, 55, 60, 67, 73, 79, 86, 93, 101, 108, 116, 124, 133, 141, 150, 159, 168, 178, 187, 197, 207, 217, 228, 238, 249, 260, 271, 282, 293, 305, 316, 328, 340, 351, 363, 375, 388, 400, 412, 424, 437, 449, 462, 474, 487, 499


I have tried writing code in MATLAB but I am not getting the exact output. lease tell me the coding procedure to obtain FFT.

• Why not use fft()? Or are you supposed to write your own implementation of a DFT/FFT? If you just want other users to provide code, then this question is off-topic on this site and will be closed. Feb 19 '15 at 8:04
• What output do you expect and what do you get?
– Deve
Feb 19 '15 at 8:06
• This might help: dsp.stackexchange.com/questions/20212/…
– Rhei
Feb 19 '15 at 12:13