PerformanceAnalytics apply.rolling with NAs
On Fri, 2011-09-02 at 13:55 +0200, Dean Marks wrote:
My use case requires that I determine rolling returns for a collection of stocks where in some cases data is missing (repressented by NAs), for example if a stock did not exist for a period of time. I don't mean to frustrate you but if I go into the use case further it might unnecessarily complicate things. My work around, in any case, is simply to test for these cases prior to calling apply.rolling.
OK, now we're getting somewhere. You could apply apply.rolling by column, but this won't give you comparable results for the rolling return case. You could aggregate your returns to some lower-frequency where all the indices will agree and you only have leading NA's to deal with. Or, you could see ?zerofill since an NA return is equivalent to a zero return (unless your manager is not reporting to hide losses, but that's a different problem altogether) Regards, - Brian
Brian G. Peterson http://braverock.com/brian/ Ph: 773-459-4973 IM: bgpbraverock