Hi Sarah, that works perfectly, thank you!

Mark Na


On Fri, Jan 18, 2013 at 5:23 PM, Sarah Goslee <sarah.goslee@gmail.com>wrote:

> Hi,
>
> You need to assign the result of the function to an object:
>
> dd1 <- dredgeit(lm1)
>
> On Fri, Jan 18, 2013 at 6:17 PM,  <mtb954@gmail.com> wrote:
> > Dear R-helpers,
> >
> > I have run the code below which I expected to make an object called dd1,
> > but that object does not exist.
> >
> > So, in summary, my problem is that my function is meant to make an object
> > (dd1), and it does indeed make that object (I know that the last line of
> > the function prints it out) but then, after the function has run, the
> > object has disappeared.
> >
> > It's late on a Friday so I may be overlooking something obvious, but I'd
> > appreciate your help if you can see what I'm doing wrong.
> >
> > Many thanks,
> >
> > Mark Na
> >
> >
> >
> > rm(list=ls())
> >
> > #LOAD package, data, and keep clean copies of data
> > library(reshape2); library(MuMIn);library(AICcmodavg)
> > birdmatrix<-read.csv("birdmatrix.csv",stringsAsFactors=FALSE);
> > birdmatrixclean<-birdmatrix
> > habitatmatrix<-read.csv("habitatmatrix.csv",stringsAsFactors=FALSE);
> > habitatmatrixclean<-habitatmatrix
> > traits<-read.csv("traits.csv",stringsAsFactors=FALSE);
> traitsclean<-traits
> > birdhabitat<-merge(birdmatrix,habitatmatrix,by="SARBASINYEAR") #merge
> bird
> > and habitat data
> > data<-birdhabitat; data$SAR<-substr(data$SARBASINYEAR,1,3) #convenience;
> > create SAR variable
> >
> > #make a FUNCTION to combine variables into models
> > dredgeit<-function(lm1){
> > dd1<-dredge(lm1,eval=FALSE) #create all possible combinations
> > dd1<-gsub("formula = ","",dd1,fixed=TRUE) #delete characters
> > dd1<-gsub(" + 1","",dd1,fixed=TRUE) #delete characters
> > dd1#inspect model formulae
> > }
> >
> > lm1<-lm(data$BiRich.o~log(data$HaArea,10)+log(data$HaPeri,10)) #saturated
> > submodel
> > dredgeit(lm1)
> >
> --
> Sarah Goslee
> http://www.functionaldiversity.org
>

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