understanding complex fft results i use  this for complex fft. 

Output expected

$fft[3].real= 32$ (peak at 3rd bin)

$fft[61].real= 32$ ((peak at negative frequency pair of 3rd bin)) 

All other values negligibly small

The input is

$ y.real = \sin (2\pi*3i/64)$ where $i = 0 \to 63$

$ y.imaginary = \sin (0*3i/64)$ where $i = 0 \to 63$ (all zero)

The output i got

$fft[3].imaginary = -32$ (peak at 3rd bin)

$fft[61].imaginary = 32$ ((peak at negative frequency pair of 3rd bin))

All other values negligibly small

This is the first time i am working with complex input fft. Can somebody explain me why i am getting peaks in imaginary part and not in real part of fft. As of my understanding doing Real FFT is nothing but using one half of input as Real part input and other half as Imaginary part input to the Compelx radix 2 FFT algorithm [i remember from John G Proakis textbook]. But i don't understand why this pseudo complex signal produces this kind of output. Also can someone explain me the phase information of this pseudo complex 
wave ?
Your expected output can be achieved when the input is as follows:

real part = cos(2*pi*[0:63]*3/64)

imag part = 0

So I think you have a couple of issues:


You are missing a factor 1/64 in your description of the input above.
You should use cos() instead of sin() for the real part of the input.


Try fixing issue 1 in your post, and try fixing issue 2 in your code.