[R] FFT - (STATS) - is this correct?

From: <renata.camargo05_at_ntlworld.com>
Date: Wed, 30 Jul 2008 12:14:17 +0100


Hello,

I have calculated the fourier transform of the series enclosed at the end of this message, by doing:  

library(stats)
x <- readLines("file1.txt")
x.num <- as.numeric(x)
ft.x.num <- fft(x.num)

My question is: why is the first value (Real) of ft.x.num that big? (954.833870) all the other values are much smaller. Am I doing something wrong?

Could you please help me to understand that?

Many thanks, Renata

2.24791
6.39824
7.43533
7.21367

11.2164
7.29183
9.72807
12.8445
12.4819
8.18952
6.38345
9.98463
6.25724
7.97327
8.9676
8.27709
14.8272
13.4908
11.876

11.4889
11.3161
9.79778
8.09873
4.43935
5.30657
9.37819

0
8.09507
10.9567
10.5478
12.6661
13.8612
14.025
13.9403
11.5847
9.50861
7.81196
5.42222
5.27313
4.16159

3.83932
8.95892
11.9548
12.7598
11.6816
13.3388
13.1956

9.50887
12.4671
11.2608
12.6553
5.63253
4.18556
4.47097

9.13142
5.29101
11.3582
7.5489
13.0371
9.26487
11.6458
6.26179
10.4051
11.7282
9.36171
10.7723
4.90151
4.25747
6.95437
6.17832
11.59

13.894
10.8935
8.19078
6.27219
6.74875

10.076
6.47078
11.1408
6.48286
10.4232
9.23548
11.199
7.97828
13.1261
12.1624
7.90476
11.7495
14.0312
9.97212
11.3685
12.6093
4.68484
4.72131
5.10963
8.1693
8.21239

10.6743
5.39084
11.1944
12.4415
8.0419
5.62567
12.2756
0

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