On 14/05/2010 5:00 PM, Ted Byers wrote:
I started a brand new session in R 2.10.1 (on Windows).
If it matters, I am running the community edition of MySQL 5.0.67, and it is
all running fine.

I am just beginning to examine the process of getting timer series data from
one table in MySQL, computing moving averages and computing a selection of
estimates based on relations among moving averages of different variates,
and storing all the results in another table in MySQL.

The very first thing I did in this session was execute the following two
commands:

Sys.setenv(MYSQL_HOME='c:/MySQL')
library(RMySQL)

The output I got was:

Loading required package: DBI
Warning message:
In inDL(x, as.logical(local), as.logical(now), ...) :
  DLL attempted to change FPU control word from 8001f to 9001f

Now, I write programs in relatively high level languages (C++, perl, Java,
and now R), and NEVER even consider twiddling with FPU control words or
playing with registers on the processor.  I have never gotten this close to
the hardware since I messed with video memory in the old days when I wrote
computer based teaching materials on DOS and had to get acceptable
performance out of the hardware available way back then..  Consequently, I
have no idea what this warning means or what I ought to do about it.  I
assume the DLL it is referring to is
libmySQL.dll<http://www.stat.berkeley.edu/classes/s133/libmySQL.dll>,
which RMySQL needs.  But I have no idea either why it would do what R says
it is doing or why it matters to me, or what I ought to do about it.

I'd appreciate any info you can provide.


That message means that the RMySQL libraries are trying to mess with the precision of the computations in the rest of your session. It might be safe; R fixes the first attempt. But if the libraries try again, R won't fix them, and the rest of your computations will be less accurate than they should be. It's probably not safe to ignore the warning. (This might be unintentional; many Microsoft libraries do this. But it is unsafe to use them.)

The safe advice is to recompile the relevant libraries in an environment that doesn't mess with things that don't belong to it. If this is impractical, another safe alternative is to just stop using that package. If this is also impractical, then you should expect your computations in R to be less accurate than they should be, and you should complain to the supplier of the badly written library that causes the problems.

Duncan Murdoch

______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.

Reply via email to