[R] Following progress in a lapply() function

[Blanchette, Marco]

Dear all,

I am processing a very long and complicated list using lapply through a custom function and I would like to generate some sort of progress report. For instance, print a dot on the screen every time 1000 item have been process. Or even better, reporting the percent of the list that have been process every 10%. However, I can't seem to figure out a way to achieve that.

For instance, I have a list of 50,000 slots:

aList <- replicate(50000,list(rnorm(50)))

That need to be process through the following custom function:

myFnc <- function(x){
     tTest <- t.test(x)
    return(list(p.value=tTest$p.value,t.stat=tTest$stat))
}

Using an lapply statement, as in:

myResults <- lapply(aList, myFnc)

The goal would be to report on the progress of the lapply() function during processing.

Any suggestion would be greatly appreciated.

Thanks

Marco


--
Marco Blanchette, Ph.D.
Assistant Investigator
Stowers Institute for Medical Research
1000 East 50th St.

Kansas City, MO 64110

Tel: 816-926-4071
Cell: 816-726-8419
Fax: 816-926-2018