#ts with a freq=1
d <- ts(x)
#it seems that this is an oscillating signal of ~ a day
plot(d)
#spectrogram which shows that the main frequency component is ~ 0.7.  this
translates to about a day (1.3 or so)
sec.pgram(d)

On Wed, Jul 30, 2008 at 7:14 AM, <renata.camargo05@ntlworld.com> wrote:

> 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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>



-- 
Let's not spend our time and resources thinking about things that are so
little or so large that all they really do for us is puff us up and make us
feel like gods. We are mammals, and have not exhausted the annoying little
problems of being mammals.

-K. Mullis

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