I'm fighting with a strange problem in R. I use an old version of Rcpp to integrate R with some C++ (sadly upgrading is not an option!), the Rcpp I use is the old RccpTemplate one. However I doubt the problem is in there.
I have some R code which runs fine most of the time, but on occasion (especially when processing a large amount of data) fails mysteriously with Value of SET_STRING_ELT() must be a 'CHARSXP' not a 'character'
It always fails in list operations, e.g.:
res[["blabl开发者_运维知识库a"]] = r
But if I use options(error=recover)
and attempt the same after the error, the assignment can be performed with no problems. The C++ only deals with numeric vectors and is actually far away in time an code from the assignments that fail.
So my vague question is: what are the most common causes of such behaviour? Bad memory? Bad objects (perhaps bad RcppResultSet
)? I'm having troubles attacking this issue...
For completeness:
platform i386-pc-solaris2.10
arch i386
os solaris2.10
system i386, solaris2.10
status
major 2
minor 10.1
year 2009
month 12
day 14
svn rev 50720
language R
This is coming from an error in C code, likely in a package that you are using (not R itself). Either the C code is written incorrectly and you only sometimes evaluate that code branch, or the C code is written incorrectly and it corrupts memory. Likely this requires a C debugger; I'm not sure about Solaris, but on Linux I'd create a script that reliably reproduces the error (this can take some work, but is an essential step) then do
R -d gdb
gdb> r # (r)un R
> ^C ## cntrl-C key, breaks into the debugger
gdb> b Rf_error # set breakpoint when error occurs; tab completion available
gdb> c # continue in R
> source("test-script.R") # [error occurs]
gdb> bt # backtrace -- current call stack, from Rf_error entry
gdb> up # move up the stack; use this to get to package C code
and then it's careful scrutiny of the code, especially looking for mis-use of PROTECT
. See gdb help
. I'd strongly suggest updating R and your packages, since bugs do get fixed and you're about to invest a significant amount of time in this.
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