[R] Non-numeric argument to fft

[rkevinburton at charter.net]

If this is the case then how to I take a list of numbers (residuals in this case) and create anothe list that is longer and padded by zeros? Maybe fft already does this for me but as I understood it I need to pass an vector to the fft that is of a power of 2 length. If I still need to do this then is there something wrong with the code below?

Thank you.

Kevin


---- Uwe Ligges <ligges at statistik.tu-dortmund.de> wrote: 
> 
> 
> rkevinburton at charter.net wrote:
> > I am calling fft and getting a "non-numeric" error:
> > 
> > +         fit <- lm(Quantity ~ DayOfYear, .sublist)
> > +         # Make the time series
> > +         x <- as.numeric(rep(0,512))
> > +         x <- merge(residuals(fit), x)
> > +         # Transform range to -pi - pi
> > +         x <- x - pi
> > +         x <- x * (2 * pi)/(max(x) - min(x))
> > +         fft(x) 
> > 
> > Error in fft(x) : non-numeric argument
> > 
> > How can I tell what the non-numeric argument is? There is only one argument.
> > 
> > What am I doing wrong?
> 
> 
> I guess merge() does something different from what you expect and your x 
> is a data.frame rather than a vector now....
> 
> Uwe Ligges
> 
> 
> 
> > Thank you.
> > 
> > Kevin
> > 
> > 
> > 
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