Thank you Henrik,
>>>>> "HenrikB" == Henrik Bengtsson <[EMAIL PROTECTED]>
>>>>> on Tue, 26 Feb 2008 22:03:24 -0800 writes:
{with many superfluous empty statements ( i.e., trailing ";" ):
HenrikB> x <- rnorm(1e6);
[................]
HenrikB> y <- log2(x); # or log10(x)
HenrikB> w <- warnings();
HenrikB> print(object.size(w));
HenrikB> ## [1] 8000536
HenrikB> str(w);
HenrikB> ## List of 1
HenrikB> ## $ NaNs produced: language log(c(2.12082478659910,
HenrikB> 1.40263187453398, 1.574125429
HenrikB> ## 83486, -0.816399069824751, 0.215940065840533, 1.20975177084379,
HenrikB> -0.340287874362
HenrikB> ## 813, 0.117151537611550, ...
HenrikB> ## - attr(*, "dots")= list()
HenrikB> ## - attr(*, "class")= chr "warnings"
HenrikB> Note also how long it takes to display and str() the warning.
Yes, indeed.
It's a subtle problem and happens
because in do_log1arg() a new call is constructed in which 'x'
has already been evaluated.
A subtle fix to the subtle problem
is to replace CAR(args) by CADR(call) in there
--- arithmetic.c (Revision 44626)
+++ arithmetic.c (working copy)
@@ -1372,7 +1372,9 @@
if(PRIMVAL(op) == 10) tmp = ScalarReal(10.0);
if(PRIMVAL(op) == 2) tmp = ScalarReal(2.0);
- PROTECT(Call = lang3(install("log"), CAR(args), tmp));
+ /* CADR(call) instead of CAR(args), since 'args' have been
+ * evaluated in Dispatch*(..) above : */
+ PROTECT(Call = lang3(install("log"), CADR(call), tmp));
res = eval(Call, env);
UNPROTECT(1);
return res;
-----
That does fix the problem you've reported (and passes "make check")
but I'm not quite at ease with it, since it will lead to
effectively evaluate the argument *twice*.
A different approach that I'd find cleaner
would be to *not* construct and eval() a
new Call inside do_log1arg, but I assume there had been a good
reason for doing things they way they are now...
Martin Maechler, ETH Zurich
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