[R] pairs, panel.functions, xlim and ylim

["Jens Oehlschlägel"]

Valerie,

A bit ugly, because you must ignore some warnings,
but for me works the code below.

Best


Jens Oehlschlägel


x <- rnorm(100, sd=0.2)
x <- cbind(x=x-0.1, y=x+0.1)
pairs(x
, panel=function(x,y){
  function to be called with xlim=, ylim= parameters
	points(x, y)
	abline(0,1)
  }
)

pairs(x
, panel=function(x,y, ...)
  { # adding the three points here allows your panel function to accept the
additional xlim=, ylim= parameters
   	points(x, y)
	abline(0,1)
  }
, xlim=c(-1, 1)
, ylim=c(-1, 1)
)


> I have the following problem.
> I wanted to get a matrix of scatterplots and I used pairs.
> I wanted to add the line y=x in each plot and I created a panel 
> function for this scope.
> I used points and abline in the following way:
> 
> ## put y=x in each plot
>      panel.lin<- function(x, y)
>      {
>          points(x,y, pch=21, bg=par("bg"), col = "black",cex=2)
>          abline(0,1,lwd=2, col="red")
>      }
> 
> and it works.
> Now, I want that each plot has the same scale on the axis and I try 
> with this modification:
> 
> ## put y=x in each plot - same scale for all the plots
>      panel.lincor<- function(x, y)
>      {
>          points(x,y, pch=21, bg=par("bg"), col = 
> "black",cex=2,xlim=c(-1,1),ylim=c(-1,1))
>          abline(0,1,lwd=2, col="red")
>      }
> 
> but R tells me that xlim and ylim couldn't be set in high level plot 
> functions.
> I try to use plot() instead of points, but I realized immediately that 
> I can't use plot as a panel function.
> I know I could have added xlim and ylim directly in pairs() function, 
> if I hadn't had a panel function, but I need the line y=x in every plot 
> and I don't know other ways to get it.
> Any idea?
> Thank you very much
> Valeria Edefonti

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