Reset par to the default values at startup

This is hacky, but:

resetPar <- function() {
    dev.new()
    op <- par(no.readonly = TRUE)
    dev.off()
    op
}

works after a fashion, but it does flash a new device on screen temporarily...

E.g.:

> par(mfrow = c(2,2)) ## some random par change
> par("mfrow")
[1] 2 2
> par(resetPar())     ## reset the pars to defaults
> par("mfrow")        ## back to default
[1] 1 1

Every time a new device is opened par() will reset, so another option is simply do dev.off() and continue.

From Quick-R

par()              # view current settings
opar <- par()      # make a copy of current settings
par(col.lab="red") # red x and y labels 
hist(mtcars$mpg)   # create a plot with these new settings 
par(opar)          # restore original settings