how to manipulate ... in the argument list
Duncan suggested to use the argument explicitly and combine it with
the missing function which is for this problem also my preferred
solution:
image.2 <- function(x, col , breaks, ...){
# function is manipulating colors (adding a few)
# since it changes colors it needs to update breaks if defined.
if( !missing(breaks) ){
#manipulate breaks
image(x, col, breaks ,...)
}else{
image(x,col ,...)
}
}
It is good to know that I also could have used do.call.
I also learned yesterday that it is better to search for dot dot dot
argument or for elipsis instead of ...
best
On 11 May 2016 at 15:45, Vito M. R. Muggeo <vito.muggeo at unipa.it> wrote:
Hi Witold, use do.call() list.args<-list(...) #modify 'list.args' (add/delete/modify) do.call(image, list.args) best, vito Il 11/05/2016 10.45, Witold E Wolski ha scritto:
Hi,
I am looking for a documentation describing how to manipulate the
"..." . Searching R-intro.html gives to many not relevant hits for
"..."
What I want to do is something like this :
image.2 <- function(x, col , ...){
# function is manipulating colors (adding a few)
# since it changes colors it needs to update breaks if defined.
breaks <- list(...)$breaks
if( !is.null( list(...)$breaks ) ){
#manipulate breaks
image(x, col, breaks = breaks ,...)
}else{
image(x,col ,...)
}
}
but in order to get it working I will need to remove breaks from ...
since otherwise I am getting multiple defined argument for breaks.
So how to manipulate the "..." argument? Or should I use a different
pattern
best
-- ============================================== Vito M.R. Muggeo Dip.to Sc Statist e Matem `Vianelli' Universit? di Palermo viale delle Scienze, edificio 13 90128 Palermo - ITALY tel: 091 23895240 fax: 091 485726 http://dssm.unipa.it/vmuggeo Associate Editor, Statistical Modelling ===============================================
Witold Eryk Wolski