[Rd] as.data.frame: Error in "names<-.default" (PR#7808)
andy_liaw at merck.com
andy_liaw at merck.com
Sun Apr 24 01:00:12 CEST 2005
> From: Robert.McGehee at geodecapital.com
>
> Hello,
> I found a potential problem in R 2.1.0 (and R 2.0.1)
>
> I expect that
>
> > tmp <- FUN(x1, x2, x3, x4)
> > as.data.frame(tmp)
>
> is the same as
> > as.data.frame(FUN(x1, x2, x3, x4))
>
> since the tmp variable in this case is unnecessary.
>
> However, below I will demonstrate that under an odd set of
> conditions, I
> can correctly perform as.data.frame(tmp), but not
> as.data.frame(FUN(x1,
> x2, x3, x4)).
>
> ## This code works correctly
> FUN <- function(x1, x2, x3, x4)
> cbind(x1[, 1, 1:2], x1[, 2, 1:2])[, 1]
>
> x1 <- array(1:9, c(3, 3, 3))
> tmp <- FUN(x1[1:3, , ], x2 = c("a", "b"), x3 = c("a", "b"),
> x4 = c("a",
> "b"))
>
> ## Works correctly
> as.data.frame(tmp)
>
> tmp
> 1 1
> 2 2
> 3 3
>
>
> ## This (supposedly equivalent) code gives an error
>
> as.data.frame(FUN(x1[1:3,,], x2 = c("a", "b"), x3 = c("a", "b"), x4 =
> c("a", "b")))
>
> Error in "names<-.default"(`*tmp*`, value = c("FUN(x1[1:3, , ], x2 =
> c(\"a\", \"b\"), x3 = c(\"a\", \"b\"), x4 = c(\"a\", ", :
> 'names' attribute [2] must be the same length as the vector [1]
>
> Note, that while the extra (unused) arguments in FUN seem unnecessary,
> as well as the odd indexing, the problem disappears when I remove the
> extraneous values. Unfortunately, I have not found a more
> elegant way to
> present this problem, but hopefully this code will be helpful.
The basic problem, I think, boils down to something like this:
> f <- function(x) deparse(substitute(x))
> f(FUN(x1[1:3,,], x2=c("a","b"), x3=c("a", "b"), x4=c("a", "b")))
[1] "FUN(x1[1:3, , ], x2 = c(\"a\", \"b\"), x3 = c(\"a\", \"b\"), x4 =
c(\"a\", "
[2] " \"b\"))"
which is caused by deparse() chopping up the expression. The fix would be
to set the width.cutoff argument to something large. Here's a proposed
patch:
--- R-2.1.0/src/library/base/R/dataframe.R 2005-04-18
06:19:15.000000000 -0
400
+++ R-2.1.0-fix/src/library/base/R/dataframe.R 2005-04-22
23:17:18.972665600 -0
400
@@ -114,7 +114,7 @@
as.data.frame.vector <- function(x, row.names = NULL, optional = FALSE)
{
nrows <- length(x)
- nm <- deparse(substitute(x))
+ nm <- deparse(substitute(x), width.cutoff=500)
if(is.null(row.names)) {
if (nrows == 0)
row.names <- character(0)
@@ -235,7 +235,7 @@
as.data.frame.model.matrix(x, row.names, optional)
else { # as.data.frame.vector without removing names
nrows <- length(x)
- nm <- deparse(substitute(x))
+ nm <- deparse(substitute(x), width.cutoff=500)
if(is.null(row.names)) {
if (nrows == 0)
row.names <- character(0)
(I used width.cutoff=500, as ?deparse says that the max. I'd imagine the
number of characters allowed for valid symbol names in R is probably lower
than that?)
Andy
> Robert
>
> Robert McGehee
> Geode Capital Management, LLC
> 53 State Street, 5th Floor | Boston, MA | 02109
> Tel: 617/392-8396 Fax:617/476-6389
> mailto:robert.mcgehee at geodecapital.com
>
>
>
> This e-mail, and any attachments hereto, are intended for
> us...{{dropped}}
>
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