On Mon, 8 Mar 2004, Adrian Trapletti wrote:I think, this is more a philosophical question, if weekends represent missing or non-existent values. One can find arguments for both.
The na.omit.ts() method fails when the time series contains internaltry na.remove from tseries. This is, e.g., useful when removing weekends (NA prices) from financial data, i.e., switching from physical time to business time.
NA's. How can these automatically be removed?
That may well not be appropriate though. NA denotes a missing and not a non-existent value,
and for example removing non-trading days in just one market it probably not appropriate (as information accrues in other markets).I partly agree with you. Sometimes it is not appropriate and it might be better to use, e.g., a state-space model which can work with NA's. But from my experience in financial markets, it is often not worth considering these more complex approaches, since they don't generate additional profits. Other effects often dominate...
The issue is not `How can the na.action be activated correctly?', but
`What is the appropriate na.action?', and the answer is usually `none of them'.
But anyhow, I find it good if the user can choose between the different options and decide himself.
Error in na.omit.ts(as.ts(x)) : time series contains internal NAsspectrum(ts.mNDII, na.action=na.omit)
How can the na.action be activated correctly?
best Adrian
Dr. Adrian Trapletti Trapletti Statistical Computing Wildsbergstrasse 31, 8610 Uster Switzerland Phone & Fax : +41 (0) 1 994 5631 Mobile : +41 (0) 76 370 5631 Email : mailto:[EMAIL PROTECTED] WWW : http://trapletti.homelinux.com
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