R help - Aug 2010 - aggregate with cummax ??

Hello

I have a time series (with index of type chron) and I need to calculate the   
cummax(mydata)-mydata
on every day separately.
I've tried this
aggregate(mydata, as.date, cummax)
but aggregate can only produce a single scalar result for each subset
instead of a vector.

I've tried with tapply and lapply but I don't know how to do it.

Can anyone help me, plese


cheers

-- 
View this message in context:
http://r.789695.n4.nabble.com/aggregate-with-cummax-tp2331991p2331991.html
Sent from the R help mailing list archive at Nabble.com.

Hi

Just in case somebody could be interested I've found that 

unlist(lapply(split(mydata,as.Date), cummax))

could make the job
but I don't know if it's the proper way if I want to use zoo objects.

Any suggestion??

-- 
View this message in context:
http://r.789695.n4.nabble.com/aggregate-with-cummax-tp2331991p2332653.html
Sent from the R help mailing list archive at Nabble.com.