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hanncplx

void hanncplx( int * x, int N, int * blockexp );

Description

Convolves an N-point complex spectrum with the three-point Hann kernel. The filtered spectrum replaces the original spectrum.

The function produces the same results as would be obtained by multiplying the corresponding time sequence by the Hann raised-cosine window.

The zero-crossing width of the main lobe produced by the Hann window is 4 DFT bins. The adjacent sidelobes are 32 db below the main lobe. Sidelobes decay at an asymptotic rate of 18 db per octave.

N must be a power of 2 and between 4 and 1024. An invalid N causes a RANGE exception.

Parameters

x

Pointer to N-element array of complex fractions.

N

Number of complex elements in array x.

blockexp

Pointer to integer block exponent.

Library

FFT.LIB

See also

fftcplx, fftcplxinv, fftreal, fftrealinv, hanncplx, powerspectrum