[R] Jitter in correlation matrix?

[Mehmet Atif Ergun]

Hi,

I am just starting to use R for a graduate course, and I like how the
correlation matrix at
http://addictedtor.free.fr/graphiques/RGraphGallery.php?graph=137

I did something similar by copying from the examples(pairs), but it
seems that I need to jitter the bottom panel...  and I have no idea how
to do that, and I mean no idea at all. I'd appreciate any help... 

Here are the graphs: 
http://socy602.pbwiki.com/f/dep_correlationmatrix.jpeg
http://socy602.pbwiki.com/f/indep_correlationmatrix.jpeg

And this is the code I used to produce the graphs (not that I
understand it, but):

######################
# Primary Component Analyses
######################

######################
# Dependent variables
######################

# List of these variables: 
#  langfamr , ethdifxx , catness , gc7 , gc8r , gc12 , culdifxx , poldifxx , ecdifxx 
######################
# Look at correlation matrix for these
cor(MAR[,c("langfamr" , "ethdifxx" , "catness" , "gc7" , "gc8r" , "gc12" , "culdifxx" , "poldifxx" , "ecdifxx" )], use="complete.obs")
# Big time correlation matrix
 panel.cor <- function(x, y, digits=2, prefix="", cex.cor)
{
    usr <- par("usr"); on.exit(par(usr))
    par(usr = c(0, 1, 0, 1))
    r <- abs(cor(x, y))
    txt <- format(c(r, 0.123456789), digits=digits)[1]
    txt <- paste(prefix, txt, sep="")
    if(missing(cex.cor)) cex <- 0.8/strwidth(txt)
    text(0.5, 0.5, txt, cex = cex * r)
}
MAR.omitdep <- na.omit(MAR[,c("langfamr" , "ethdifxx" , "catness" , "gc7" , "gc8r" , "gc12" , "culdifxx" , "poldifxx" , "ecdifxx" )])
pairs(MAR.omitdep[,c("langfamr" , "ethdifxx" , "catness" , "gc7" , "gc8r" , "gc12" , "culdifxx" , "poldifxx" , "ecdifxx" )], lower.panel=panel.smooth, upper.panel=panel.cor)
# Save it
dev.copy(jpeg,filename="dep_correlationmatrix.jpeg",height=600, width=800,bg="white")
dev.off()

######################
# Independent variables
######################

# List of variables
#  poldis , polres , ecdis , culres , gcc1 
######################
# Look at the correlation matrix
cor(MAR[,c("poldis" , "polres" , "ecdis" , "culres" , "gcc1" )], use="complete.obs")
# Big time correlation matrix
 panel.cor <- function(x, y, digits=2, prefix="", cex.cor)
{
    usr <- par("usr"); on.exit(par(usr))
    par(usr = c(0, 1, 0, 1))
    r <- abs(cor(x, y))
    txt <- format(c(r, 0.123456789), digits=digits)[1]
    txt <- paste(prefix, txt, sep="")
    if(missing(cex.cor)) cex <- 0.8/strwidth(txt)
    text(0.5, 0.5, txt, cex = cex * r)
}
MAR.omitindep <- na.omit(MAR[,c("poldis" , "polres" , "ecdis" , "culres" , "gcc1" )])
pairs(MAR.omitindep[,c("poldis" , "polres" , "ecdis" , "culres" , "gcc1" )], lower.panel=panel.smooth, upper.panel=panel.cor)
# Save it
dev.copy(jpeg,filename="indep_correlationmatrix.jpeg",height=600, width=800,bg="white")
dev.off()

Thanks a lot in advance,
Sincerely,
Mehmet.