FFT代码
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cludestdiohi
cludemathhi
cludestdlibh
defi
eN864输入样本总数defi
eM3DFT运算层数2mNdefi
ePI31415926
floattwiddleN2100707000707
floatx_rN11110000输入数据，此处设为8个
floatx_iN
N8
初始化输出虚部staticvoidfft_i
itvoid
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tifori0iNix_ii00
反转算法将时域信号重新排序这个算法有改进的空间staticvoidbitrevvoid
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tp1qii
tbit_revNfloatxx_rN
bit_rev00whilepN
forq0qpq
bit_revqbit_revq2bit_revqpbit_revq1p2
ffori0iNixx_rix_ri
fori0iNix_rixx_rbit_revi
voidfftvoidfpfope