f (t), [0, ] ak bk (2) (3).
() ( 1).
() f (t) , . k ( ) j k ( ) w k = kw 1.
k j k () (4). , , ( 2 1).
1.
2.
, , Mathcad.
a 0, a 1, ..., ak, b 1, b 2, ..., bk ( A 1, A 2, ..., Ak, j 1, j 2, ..., j k) y = f (t), [0, ] .
(7) (8) |
D t = T / N , y = f (t).
Mathcad () . , 2 m (m ) , . f (t), , fft.
fft(v). 2 m - v, v , f (t).
1 + 2 m - 1 - . ak bk, .
ifft :
ifft(v) v . v 1 + 2 m - 1.
2 m .
3 .