I try to use cufftExecR2C and print out the result. That show the complex fft result for the input

```
0 1 2 3
4 5 6 7
8 9 10 11
12 13 14 15
```

is

1.2e+02+ 0i -8+ 8i -8+ 0i -32+ 32i

0+ 0i 0+ 0i -32+ 0i 0+ 0i

0+ 0i -32+ -32i 0+ 0i 0+ 0i

-32+ -32i 0+ 0i 0+ 0i 0+ 0i

however the right result with cufftExecC2C is

1.2e+02+ 0i -8+ 8i -8+ 0i -8+ -8i

-32+ 32i 0+ 0i 0+ 0i 0+ 0i

-32+ 0i 0+ 0i 0+ 0i 0+ 0i

-32+ -32i 0+ 0i 0+ 0i 0+ 0i

that is the same with result i got from Matlab.

Can some one explain what happen with cufftExecR2C. Is that a bug or smth else

How can i use that one for FFT convolution .

Thank you