
Thank you for your response and assisting me with clarifying my question.  Here is a portion of the code I am using:

xxx04 <- ppp(x=mpb04$Easting, y=mpb04$Northing, window=tpi1.win)
dens2004<-density(xxx04)
save(dens2004, file="dens2003.Rdata"
dens2004.load<-load("dens2004.Rdata")
dens2004.im<-as.im(dens2004.load, W=tpi1.win)

fm <- ppm(xxx04, ~x + y + density, Poisson(), covariates=list(dens2004.load) #"Error in model.frame.default(formula=fmla, data=glmdata, subset=(.mpl.SUBSET == : invalid type(closure) for variable 'density')

I hope this elucidates the problem further.  Any help you can provide would be wonderful.  Thank you.

Sincerely,





Honey-Marie de la Giroday

> Date: Tue, 24 Jun 2008 11:40:42 +0200
> From: Roger.Bivand@nhh.no
> To: girodayh@unbc.ca
> CC: r-sig-geo@stat.math.ethz.ch
> Subject: Re: [R-sig-Geo] Coercing character to image
> 
> On Tue, 24 Jun 2008, Honey Giroday wrote:
> 
> >
> >
> > Hi,
> >
> > I'm currently trying to use save() on a density plot (i.e. an image) 
> > that takes a long time to generate (using density(x)).  I want to be 
> > able to use the saved dataset as a covariate in ppm.  However, once my 
> > image is saved and loaded back in it is a character object instead of an 
> > image.  I tried using as.im to coerce the object to an image; however, I 
> > get an error message.
> >
> > Does anyone have a method for converting a character object to an image 
> > object?
> 
> No, because you have not provided a code example to show what you did 
> (wrong). Please create an example using a data set included in spatstat, 
> reproducing your problem. We cannot see over your shoulder. My guess is 
> that your question is not the right question, because the problem arose 
> earlier in the workflow.
> 
> Roger
> 
> >
> > Sincerely,
> >
> >
> >
> >
> >
> >
> > Honey-Marie de la Giroday
> >
> > _________________________________________________________________
> >
> >
> > 	[[alternative HTML version deleted]]
> >
> > _______________________________________________
> > R-sig-Geo mailing list
> > R-sig-Geo@stat.math.ethz.ch
> > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >
> 
> -- 
> Roger Bivand
> Economic Geography Section, Department of Economics, Norwegian School of
> Economics and Business Administration, Helleveien 30, N-5045 Bergen,
> Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43
> e-mail: Roger.Bivand@nhh.no
> 

_________________________________________________________________


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