splom, plotmath: how to add three lines of information with alignment?

Dear Baptiste,

thanks for your answer.
Unfortunately, I get the error "Error using packet 1 invalid 'times' argument" when executing your code. Hmm... not sure where the problem is.

Cheers,

Marius

On 2011-04-19, at 24:03 , baptiste auguie wrote:

Hi,

Does this help?

library(gridExtra)

my.title = function(expressions) {
?grid.table(expressions, parse=TRUE,
? ? ? ? ? ? theme=theme.list(gpar.corefill = gpar(fill = NA, col = NA),
? ? ? ? ? ? ? core.just = "left"))
}

e = expression(alpha,"text", italic(italic),
? ?hat(beta), integral(f(x)*dx, a, b))

library(lattice)

xyplot(1~1, panel=function(...) my.title(e) )

HTH,

baptiste



On 19 April 2011 08:43, Marius Hofert <m_hofert at web.de> wrote:

Dear expeRts,

I would like to create a scatter plot matrix with splom(). The lower panel should
contain some additional information about the samples shown in the upper panel
plot, see the splom() call below. Now two questions came up:
(1) The lower panels show "tau" and "alpha" on top of each other. How can I plot
*three* expressions on top of each other? I tried several approaches (see the trials below),
but couldn't manage to get this to work properly.
(2) Is there the possibility to plot the two/three lines (containing "tau = ..", "alpha = ..")
aligend according to the equality sign?

Cheers,

Marius


library(lattice)

f <- function(i,j) i+j

U <- matrix(runif(3000), ncol=3)

splom(U,
? ? ?superpanel=function(z, ...){
? ? ? ? ?tau <- cor(U, method="kendall")
? ? ? ? ?df=data.frame(rows=as.vector(row(tau)), columns=as.vector(col(tau)),
? ? ? ? ?vals=as.vector(tau)) # data frame of row indices, column indices, and tau values
? ? ? ? ?df=subset(df,columns<rows) # subset for lower left triangle
? ? ? ? ?with(df,{
? ? ? ? ? ? ?panel.text(x=rows, y=columns,
? ? ? ? ? ? ? ? ? ? ? ? labels=as.expression(unlist(lapply(1:length(vals),
? ? ? ? ? ? ? ? ? ? ? ? ? ? function(i) substitute(atop(tau==tau.,alpha==alpha.),
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?list(tau.=vals[i], alpha.=round(vals[i],3)) ) ))) )
? ? ? ? ?})
? ? ? ? ?panel.pairs(z, upper.panel=panel.splom, lower.panel=function(...){}, ...)
? ? ?})

## some minimal "trial" examples:
plot(0,0,main=paste("alpha=1","\n","beta=2","\n","gamma=3",sep=""))
plot(0,0,main=expression(atop(atop(alpha==1, beta==2), gamma==3)))
plot(0,0,main=paste(expression(alpha==1),"\n",expression(beta==2),"\n",
? ? ? ? expression(gamma==3), sep=""))
plot(0,0,main=substitute(paste(alpha==1,x,beta==2,x,
? ? ? ? gamma==3, sep=""), list(x="\n")))
plot(0,0,main=expression(cat(alpha==1, "\n", beta==2, "\n", gamma==3, sep="")))
plot(0,0,main=cat(expression(alpha==1), "\n", expression(beta==2), "\n",
? ? ? ? expression(gamma==3), sep=""))