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issue with output of fft

rakesh
Beginner
100 Views

Hi,

i'm evaluating fft function.

my packed format is CCS.

i'm giving real input to fft function and i'm getting complex output arranged in real aaray in R,I,R,I format.

since it's real fft so due to conjugate symmetry i 'm getting half output.

how to retrive other half of output.

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1 Reply
Ying_H_Intel
Employee
100 Views
Dear rakesh, does you mean Real FFT ouput z(n/2) CCS R0 0 R1 I1 ... Rn/2-1 In/2-1 Rn/2 0 and you want to restore another half R0 0 R1 -I1 ... Rn/2-1 -In/2-1 Rn/2 0 you may use the funciton v?Conj to Performs element by element conjugation of the vector and attach another half to your original output array. like call vcconj( n/2, z(0), z(n/2+1) ) Best Regards, Ying
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