[R] r programming help

[Peter Dalgaard]

Mohammad Ehsanul Karim <wildscop at yahoo.com> writes:

> Dear list,
> 
> Is there anyway i can make the following formula short
> by r-programming?
> 
> CYCLE.n<-c(NA,
> WET[1]*DRY[1],
> WET[1]*DRY[2]+WET[2]*DRY[1],
> WET[1]*DRY[3]+WET[2]*DRY[2]+WET[3]*DRY[1],
....

As far as I can see: 

z <- toeplitz(DRY)
z[upper.tri(z)] <- 0
c(NA, z %*% WET)

or convolve() with suitable options, padding, and/or cutting (but
beware, there could be devils in the details). convolve(WET,DRY,
type="o") gives you about twice what you need, I believe.


-- 
   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
 (*) \(*) -- University of Copenhagen   Denmark          Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)                  FAX: (+45) 35327907