Re: [Discuss-gnuradio] Why is fft output complex?

2014-10-12 Thread Robert McGwier
Brad: You are treating an FFT as if it were a spectrum analyzer which produces a magnitude or energy profile of how much signal is at a particular frequency. The FFT does much more than that. It tells not only what magnitude is at a frequency but what phase angle the signal has there. Let's

[Discuss-gnuradio] Why is fft output complex?

2014-10-11 Thread k1gto
I can't wrap my head around why fft transform of complex signal produces a complex output. After all the output reflects the amount of energy per frequency bin and frequency bins and energy are both real numbers, no?I'm trying to write a python script to analyze the energy across frequency bins

Re: [Discuss-gnuradio] Why is fft output complex?

2014-10-11 Thread jeff millar
On 10/11/2014 05:38 PM, k1...@comcast.net wrote: I can't wrap my head around why fft transform of complex signal produces a complex output. After all the output reflects the amount of energy per frequency bin and frequency bins and energy are both real numbers, no? I'm trying to write a

Re: [Discuss-gnuradio] Why is fft output complex?

2014-10-11 Thread Daniel Marlow
On Oct 11, 2014, at 5:38 PM, k1...@comcast.net k1...@comcast.net wrote: I can't wrap my head around why fft transform of complex signal produces a complex output. After all the output reflects the amount of energy per frequency bin and frequency bins and energy are both real numbers, no?

Re: [Discuss-gnuradio] Why is fft output complex?

2014-10-11 Thread k1gto
-gnuradio] Why is fft output complex? On 10/11/2014 05:38 PM, k1...@comcast.net wrote: I cant wrap my head around why fft transform of complex signal produces a complex output. After all the output reflects the amount of energy per frequency bin and frequency bins