- #1
btb4198
- 572
- 10
I have a working DFT and FFT now that I coded in a program ..
now from testing I can see that with both the FFT and the DFT if I just graph the Imaginary number I will get the right frequency
for example:
F[t] = 10 Sin((2 * PI * 2000 *t)/8000) 0 <t <1024
will get me
a frequency
2000 Hz and 6000 Hz now I do know that 6000 Hz is the - frequency in the sin wave
but I a graph my Real numbers I get
0 Hz
4000Hz
Why is that ?
should I only use my imaginary values and for get about my real value ?
also my magnitude for all the Frequencies are the same 65535 can I get something from that ?
now from testing I can see that with both the FFT and the DFT if I just graph the Imaginary number I will get the right frequency
for example:
F[t] = 10 Sin((2 * PI * 2000 *t)/8000) 0 <t <1024
will get me
a frequency
2000 Hz and 6000 Hz now I do know that 6000 Hz is the - frequency in the sin wave
but I a graph my Real numbers I get
0 Hz
4000Hz
Why is that ?
should I only use my imaginary values and for get about my real value ?
also my magnitude for all the Frequencies are the same 65535 can I get something from that ?