[R] time series has no or less than 2 periods

[David Winsemius]

On Oct 3, 2013, at 8:32 AM, Daniel Hickman wrote:

> Hello,
> 
> 
> 
> I have been tasked with taking an excel file that my colleague had implemented Triple Exponential Smoothing and recreate using R. 
> 
> The following image shows the before and after of smoothing out a fixed interval time series data using Triple Exponential Smoothing inside of Excel.
> 
> enter image description here

The image file formats that I know are acceptable are .ps, .pdf or .png. Not sure about jpeg.

> 
> I am trying to perform the same triple exponential smoothing in R.  I created a csv file with the before smoothing data.  The csv file is attached and can also be found here.

Need to send with .txt extension.

> 
> I found the HoltWinters method but I keep getting an error when I try to apply HoltWinters against the csv.
> setwd("C:/temp")
> data <- read.table("TripleExpSmoothingXLS.csv", header=TRUE, sep=",")
> ts <- ts(data$QtyPerWeek, frequency=52)
> HoltWinters(ts,0.46924,0.05,0.2)
> 
> This results in the following error. "Error in decompose(ts(x[1L:wind], start = start(x), frequency = f), seasonal) : time series has no or less than 2 periods"

Perhaps a data entry problem. We would need to see either the file or output of str(data).
> 
> In case it helps,  excel file with the triple exponential smoothing formulas and original data can be found here.

Again.... there is no here here.

> 
> Any advice? 
> 
> Thanks, Dan______________________________________________
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David Winsemius
Alameda, CA, USA