[R] Image display in R

[tom wright]

This peice of very useful getcell() function was posted for me on this
list by Duncan Murdoch (Thanks again Duncan). It allows the
identification of a particular plot in a matrix of plots. All you need
to do then is use this information to identify the original plot which
you can then re-plot.

###### Start Function ######
getcell <- function(pts = locator()) {
   usr <- par("usr")
   plt <- par("plt")
   mfg <- par("mfg")

   x <- pts$x
   y <- pts$y

   # convert to 0-1 plot coordinates
   px <- (x-usr[1])/(usr[2]-usr[1])
   py <- (y-usr[3])/(usr[4]-usr[3])

   # convert to 0-1 frame coordinates
   fx <- plt[1] + px*(plt[2]-plt[1])
   fy <- plt[3] + py*(plt[4]-plt[3])

   # convert to a relative cell position
   cx <- floor(fx)
   cy <- floor(fy)

   # return the absolute cell position
   list(row = -cy+mfg[1],col = cx+mfg[2])
}
####### End Function #######
#For example
Dset1<-1:10
Dset2<-rnorm(10)

oldpar<-par(mfrow=c(2,1))
plot(Dset1)
plot(Dset2)

cell<-getcell(locator(1))

if((cell$row*cell$col)<2){
	par(mfrow=c(1,1))
	plot(Dset1)
} else {
	par(mfrow=c(1,1))
	plot(Dset2)
}

I hope this gives you something to work with.
Tom

On Fri, 2005-18-11 at 09:46 -0500, Vasundhara Akkineni wrote:
> Hi all,
>  I am trying to display a matrix of plots(images), for example a 3*3 matrix
> of 9 image plots, such that when a user clicks on a image i can show the
> enlarged plot. I tried the multiple graphic device(using mfcol=c(3,3) and
> mfg), but it creates multiple plots in a single image file. So, i won't be
> able to highlight a particular plot when the user clicks on it.
>  To be more clear, can i display images in the form of a matrix in R. Are
> there any grids available? Please let me know.
>  Thanks,
> Vasu.
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
>