[R] Holt-Winters problem

[Berend Hasselman]

On 26-07-2013, at 16:18, Przemek Gawin <arl3nu at gmail.com> wrote:

> This post has NOT been accepted by the mailing list yet.
> This post was updated on Jul 26, 2013; 4:40pm.
> Hello,
> 
> Two days ago I started my journey with R, and right now I'm struck on
> Holtwinters, and have no idea, what I'm doing wrong. So now, I'll show
> step by step what I've been doing. Actually it is a part of "Introducy
> Time Series with R".
> 
> 1) I download data from
> http://www.massey.ac.nz/~pscowper/ts/motororg.dat due to port
> blockage. Save it as motororg.txt
> 
> 2) Inserting this code:
> Motor.dat <- read.table("motororg.txt", header = T)
> attach(Motor.dat)
> Comp.hw1 <- HoltWinters(complaints, beta = 0, gamma = 0)
> 
> 3) Baang! Error here.
> "Error in decompose(ts(x[1L:wind], start = start(x), frequency = f),
> seasonal) :
> time series has no or less than 2 periods"
> 

Your complaints vector is not a timeseries. 

From the section Arguments of HoltWinters:

gamma	parameter used for the seasonal component. If set to FALSE, an non-seasonal model is fitted.

So use gamma=FALSE.

Don't use attach().
Use Motor.dat$complaints in the HoltWinter call 

or

Comp.hw1 <- with(Motor.dat, HoltWinters(complaints,  beta = 0, gamma = FALSE))


Berend

> 4) Actually it has, and I turned it on with attach command?
> 
> Motor.dat
>   complaints
> 1          27
> 2          34
> 3          31
> 4          24
> 5          18
> 6          19
> 7          17
> 8          12
> 9          26
> 10         14
> 11         18
> 12         33
> 13         31
> 14         31
> 15         19
> 16         17
> 17         10
> 18         25
> 19         26
> 20         18
> 21         18
> 22         10
> 23          4
> 24         20
> 25         28
> 26         21
> 27         18
> 28         23
> 29         19
> 30         16
> 31         10
> 32         24
> 33         11
> 34         11
> 35         13
> 36         27
> 37         18
> 38         20
> 39         21
> 40          6
> 41          9
> 42         29
> 43         12
> 44         19
> 45         14
> 46         19
> 47         16
> 48         23
> 
> Can you tell me what I am doing wrong?
> 
> PS
> 
> I tried to make complaints.ts as well but I didn't work either.
> 
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