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Fast Fourier transform: Difference between revisions
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<pre>[4.0000000000000000000000000000000000000, 1.0000000000000000000000000000000000000 - 2.4142135623730950488016887242096980786*I, 0.E-37 + 0.E-38*I, 1.0000000000000000000000000000000000000 - 0.41421356237309504880168872420969807856*I, 0.E-38 + 0.E-37*I, 0.99999999999999999999999999999999999997 + 0.41421356237309504880168872420969807860*I, 4.701977403289150032 E-38 + 0.E-38*I, 0.99999999999999999999999999999999999991 + 2.4142135623730950488016887242096980785*I]</pre>
differently, and even with "graphics"
<lang parigp>install( FFTinit, Lp );
install( FFT, GG );
k = 7; N = 2 ^ k;
CIRC = FFTinit(k);
v = vector( N, i, 3 * sin( 1 * i*2*Pi/N) + sin( 33 *i*2*Pi/N) );
w = FFT(v, CIRC);
\\print("Signal");
\\plot( i = 1, N, v[ floor(i) ] );
print("Spectrum");
plot( i = 1, N / 2 , abs( w[floor(i)] ) * 2 / N );</lang>
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<pre>Spectrum
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1 64</pre>
=={{header|Pascal}}==
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