Message-ID: <877go1xifi.wl%neal@walfield.org>
Date: 2012-12-29T10:26:57Z
From: Neal H. Walfield
Subject: parallel error message extraction (in mclapply)?
In-Reply-To: <CAPr7RtXxbWs68PY2YWO0f=WVFSvcU1ztgx1aVtpOk3kdmRS=tQ@mail.gmail.com>
Hi, Ivo,
At Fri, 28 Dec 2012 16:34:03 -0800,
ivo welch wrote:
> so, it isn't obvious to me how I get to the try-error object
> list, or how to find out what triggered the abort.
A try object is an object that captures the execution context at the
time of an error. Consider the following code:
> library(multicore)
> result = mclapply(1:10, function (i) { if (i == 4) foo() else i })
Warning message:
In mclapply(1:10, function(i) { :
scheduled core 4 encountered error in user code, all values of the job will be affected
To investigate the error, we can use the try object that has been
saved in position 4:
> print(result[[4]])
[1] "Error in FUN(4L[[1L]], ...) : could not find function \"foo\"\n"
attr(,"class")
[1] "try-error"
attr(,"condition")
<simpleError in FUN(4L[[1L]], ...): could not find function "foo"
> traceback(result[[4]])
1: Error in FUN(4L[[1L]], ...) : could not find function "foo"
Neal