[R-sig-eco] Function for continuing past stop error

[Novack-Gottshall, Philip M.]

Hi all,

I'm wondering if anyone knows of a function to continue after a
stop/error call in a loop. Something akin to next, but able to deal with
a stop-error.

I'm analyzing many samples, and some statistics/models can not be
applied to certain ones. The reasons why vary across samples, so it's
not as straightforward as adding a rule like "if sample size is < x, go
to next sample." It would be easier if there was a rule like "if the
following function results in an error, go to next sample." However, all
"stops" I know of permanently end the execution, and so adding a "next"
doesn't seem to work.

Here's a contrived example showing what I mean, which executes the first
two cases, but the third "stops", preventing execution for the fourth case:

library(MASS)
set.seed(314)
size <- c(10, 20, 1, 5)
for (i in 1:4) {
     print(fitdistr(rnorm(size[i], mean=20), "gamma"))
     }

# One solution would be to add a line like:
if(size[i] < 1) next

# But in my case, there would have to be many different such "next"
rules, and some I can't figure out exactly why an error is being produced

# Can anyone point me in a useful direction? I'm looking for something like:
if(error) next

Thanks,
Phil

-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 Phil Novack-Gottshall
 Assistant Professor
 Department of Biological Sciences
 Benedictine University
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 pnovack-gottshall at ben.edu
 Phone: 630-829-6514
 Fax: 630-829-6547
 Office: 332 Birck Hall
 Lab: 107 Birck Hall
 http://www1.ben.edu/faculty/pnovack-gottshall
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