On Wed, 3 Dec 2008, William Dunlap wrote:
Brian,
Your change to src/main/attrib.c:dimnamesgets(),
--- attrib.c (revision 47045)
+++ attrib.c (working copy)
@@ -857,6 +857,9 @@
UNPROTECT(1);
PROTECT(val = newval);
}
+ if (k != length(val))
+ error(_("length of 'dimnames' [%d] must match that of 'dims'
[%d]"),
+ length(val), k);
for (i = 0; i < k; i++) {
SEXP _this = VECTOR_ELT(val, i);
if (_this != R_NilValue) {
results in array() and matrix() treating dimnames=list() differently
and I think they ought to act the same when feasible.
Also, the error message is not really the right one, as the length
of the dimnames handed to the array() or matrix() function does not
have to be the length of dim - a short one gets padded with NULL's.
(I don't know if this padding is the best thing to do -- R does it
and S+ does not -- and I think it generally reflects user error.)
Not always: setting dimnames(A)[[1]] is the crux example.
E.g., in R:
f<-function(dimnames){
mat<-try(matrix(1:6,nrow=2,dimnames=dimnames), silent=TRUE)
arr<-try(array(1:6,dim=c(2,3),dimnames=dimnames), silent=TRUE)
list(matrix=mat, array=arr, identical=identical(mat, arr))
}
f(dimnames=NULL)
$matrix
[,1] [,2] [,3]
[1,] 1 3 5
[2,] 2 4 6
$array
[,1] [,2] [,3]
[1,] 1 3 5
[2,] 2 4 6
$identical
[1] TRUE
f(dimnames=list())
$matrix
[1] "Error in matrix(1:6, nrow = 2, dimnames = dimnames) : \n length of
'dimnames' [0] must match that of 'dims' [2]\n"
attr(,"class")
[1] "try-error"
$array
[,1] [,2] [,3]
[1,] 1 3 5
[2,] 2 4 6
$identical
[1] FALSE
f(dimnames=list(Row=LETTERS[24:25])) # short dimnames
$matrix
Row [,1] [,2] [,3]
X 1 3 5
Y 2 4 6
$array
Row [,1] [,2] [,3]
X 1 3 5
Y 2 4 6
$identical
[1] TRUE
The following change to src/main/array.c makes array() and matrix()
treat dimnames=list() in the same way (equivalent to dimnames=NULL.
which is not obvious to me is correct.
--- array.c (revision 47047)
+++ array.c (working copy)
@@ -152,7 +152,7 @@
;
}
}
- if(!isNull(dimnames)) ans = dimnamesgets(ans, dimnames);
+ if(!isNull(dimnames) && length(dimnames)>0) ans = dimnamesgets(ans,
dimnames);
UNPROTECT(1);
return ans;
}
The change to attrib.c:dimnamesgets() is fine: this change to
array.c:do_matrix just avoids the call.
Bill Dunlap
TIBCO Software Inc - Spotfire Division
wdunlap tibco.com
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Prof Brian Ripley
Sent: Wednesday, December 03, 2008 9:14 AM
To: [EMAIL PROTECTED]
Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED]
Subject: Re: [Rd] Matrix dimnames crash (PR#13361)
On Wed, 3 Dec 2008, [EMAIL PROTECTED] wrote:
In Windows XP, the matrix() function crashes the program
when 'dimnames'
is an empty list:
matrix(1:4, nrow=2, dimnames=list())
# R has encountered a problem and needs to close ...
This bug is specific to WinXP, as Linux64 handles this
situation more
gracefully:
matrix(1:4, nrow=2, dimnames=list())
Error in matrix(1:4, nrow = 2, dimnames = list()) :
invalid type (environment) for 'dimnames' (must be a vector)
Actually no (the reported type is wrong, and my x86_64 Linux
system also
crashes).
This case slips though the error-checking, and I've added a
final error
check that will catch it in R-patched.
Thank you for the report.
Thanks,
Arni
R 2.8.0-patched on WinXP
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--
Brian D. Ripley, [EMAIL PROTECTED]
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
______________________________________________
R-devel@r-project.org mailing list
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--
Brian D. Ripley, [EMAIL PROTECTED]
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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