Displaying 20 results from an estimated 4000 matches similar to: "is.na<- coerces character vectors to be factors within dataframes (PR#1577)"
2002 May 20
1
(PR#1577) is.na<- coerces character vectors to be factors
The inconsistency is that you use $<- to set the column, then [[<- to
change it. Had you tried to set the column by
x[[1]] <- as.character(x[[1]])
you would have seen the problem immediately (it does not work as you would
have intended). If you want to be sure to turn off conversion to factor,
you need to set the column to class "AsIs". My belief is that
will behave
2002 Apr 30
3
rbind'ing empty rows in dataframes in 1.4.1 versus 1.5.0
Hi,
In 1.4.1, I was able to create extra "empty" rows in a dataframe as so:
> x <- data.frame(a = letters[1:3], b = 1:3)
> x
a b
1 a 1
2 b 2
3 c 3
> x[4,]
a b
NA NA NA
> rbind(x, x[4,])
a b
1 a 1
2 b 2
3 c 3
NA NA NA
> R.version
_
platform sparc-sun-solaris2.6
arch sparc
os solaris2.6
2002 Aug 28
2
NA rownames in dataframes
Hey everyone!
I am seeing strange behavior with NA in the rownames of dataframes:
> a <- data.frame(1:3, row.names = c("r1", NA, "r3"))
> cbind(a)
X1.3
r1 1
<NA> 2
r3 3
Everything works. The peculiar thing is that when the NA is in the first
row, things no longer work as I would have expected:
> b <- data.frame(1:3, row.names
2001 Oct 04
1
Strange behavior with saved character vectors containing a slash
I am seeing some strange behavior using save on a character vector containing a
slash. If this is a bug, I will happily submit it (as a single entry! ;-) ) to
r-bugs. Here is an example involving "VIA\B".
> version
_
platform sparc-sun-solaris2.6
arch sparc
os solaris2.6
system sparc, solaris2.6
status
2002 Apr 08
2
subsetting with NA's
Hi,
I often have large dataframes with many variables and many NA's, from which I
would like to subset out some rows. Here is a toy example:
> x <- data.frame(a = c("x", "y", "z"), b = c(1, NA, 5))
> x
a b
1 x 1
2 y NA
3 z 5
I realize that, if I know the values in x$b that I want to subset, things are easy:
> x[x$b %in% c(1),]
a b
1 x 1
2001 Oct 04
1
Problems merging with POSIXct objects and all = TRUE
I am having problems using merge with all = TRUE when one of the dataframes has
objects of class POSIXct. If this is a bug, let me know and I will report it to
r-bugs. Here is an example:
> version
_
platform sparc-sun-solaris2.6
arch sparc
os solaris2.6
system sparc, solaris2.6
status
major 1
2001 Nov 06
1
R CMD check, undoc and package checking
As cool and wonderful as the package checking tools for R are, I sometimes am
stymied when trying to track down a problem. For example, I occasionally see
error messages when running R CMD check like the following:
[...]
* checking Rd files ... OK
* checking for undocumented objects ... ERROR
* in parse(file, n, text, prompt) : syntax error on line 932
* in undoc(dir =
2001 Nov 29
3
package argument to library as string
The help page for library says that:
package, help: name or character string giving the name of a package.
Yet, I don't seem to be able to use a string variable here.
> version
_
platform sparc-sun-solaris2.6
arch sparc
os solaris2.6
system sparc, solaris2.6
status
major 1
2001 Sep 26
1
Characters vectors, NA's and "" in merges
I often use merge with dataframes that contain character vectors which have
elements that are sometimes "NA" (meaning the string NA, not the same thing,
obviously, as NA in a numeric or factor vector). For example, the stock ticker
for Nabisco was "NA". Unfortunately (for me), it seems like merge insists on
inserting "NA" for missing values. My question: Is there some
2001 Oct 04
1
Bug when trying to save a character vector with an embedded / (PR#1115)
Here is an example involving "VIA\B".
> version
_
platform sparc-sun-solaris2.6
arch sparc
os solaris2.6
system sparc, solaris2.6
status
major 1
minor 3.0
year 2001
month 06
day 22
language
2002 Apr 30
2
display of character NA's in a dataframe in 1.5.0
I understand that NA's in character vectors are displayed differently than NA's
in factor vectors.
> c("x", NA, "y")
[1] "x" NA "y"
> as.factor(c("x", NA, "y"))
[1] x <NA> y
Levels: x y
That seems sensible enough. But shouldn't I see the same behavior in a dataframe?
> test <- data.frame(a =
2002 Jul 10
1
bug in all.equal.character (PR#1767)
There is a bug in all.equal.character:
> all.equal.character(c("A", "B", "C"), c("A", "B", "C"))
[1] TRUE
> all.equal.character(c("A", "B", "C"), c("A", "B", NA))
Error in sum(out) : Object "out" not found
> traceback()
3: sum(out)
2: paste("`is.NA' value
2002 May 21
1
I() fails on objects of class POSIXct (PR#1587)
Although the documentation is somewhat sketchy, I() can be used to create
objects of class AsIs:
> I("a")
[1] "a"
attr(,"class")
[1] "AsIs" "character"
> I(4)
[1] 4
attr(,"class")
[1] "AsIs" "numeric"
> I(4 + 0i)
[1] 4+0i
attr(,"class")
[1] "AsIs" "complex"
>
This
2001 Aug 31
1
--quiet flag sets echo option to TRUE (PR#1083)
The help for options says:
echo: logical. Only used in non-interactive mode, when it controls
whether input is echoed. Command-line options `--quiet' and
`--slave' set this initially to `FALSE'.
I don't think that this is correct for me.
Consider the following session:
mica|junk> ls
test.R
mica|junk> cat test.R
cat("Why was this command
2002 May 11
1
vector(NA, 3) (PR#1541)
I don't seem to be able to initialize a vector of NAs. I hope this is a
bug and not a new feature (I realize I have not paid much attention to a
lot of recent discussion about NA):
platform sparc-sun-solaris2.6
arch sparc
os solaris2.6
system sparc, solaris2.6
status
major 1
minor 5.0
year
2002 Aug 15
1
order(1, na.last=NA) fails (PR#1913)
R> order(1, na.last=NA)
Error in apply(sapply(z, is.na), 1, any) :
dim(X) must have a positive length
This bug appears unrelated to PR#1906, and so the fix of 8/15 doesn't help.
It comes from the line inside order():
ok <- !apply(sapply(z, is.na), 1, any)
where z=list(1) in my example. sapply() returns a single-element vector, not a
matrix, making apply() unhappy. This might
2002 May 08
3
Suggestions for poor man's parallel processing
Almost all of the heavy crunching I do in R is like:
> for(i in long.list){
+ do.something(i)
+ }
> collect.results()
Since all the invocations of do.something are independent of one another, there
is no reason that I can't run them in parallel. Since my machine has four
processors, a natural way to do this is to divide up long.list into 4 pieces
and then start 4 jobs, each of which
1999 Apr 13
1
outer fails with group generic operations on factors (PR#166)
B <- A <- factor(c("a", "b"))
outer(A, B, "!=")
Warning: "FUN" not meaningful for factors
[,1] [,2]
[1,] NA NA
[2,] NA NA
Now, this used to work in 0.63.2, but someone `improved' outer. There
it did an implicit as.numeric. The problem is that get in match.fun does
not understand group generics, and gets
Browse[1]> FUN
2002 May 29
1
warning message for setAs when using class AsIs
This seemed too advanced for r-help and is related to the recent discussion of
character vectors in dataframes.
Following Brian Ripley's most excellent advice, we are moving to a world in
which character vectors in dataframes are always of class AsIs. The cool way of
doing this seemed to be the following:
> cat(c("x", "y", "z"), file = "test.txt",
2003 Mar 05
1
printing POSIXct values in table labels
Hi,
I think that there is something that I am misunderstanding in creating tables
using dates that are of class POSIXct. Consider:
> x <- data.frame(date = as.POSIXct(strptime(c(rep("2002-10-17", 4), rep("1999-12-08", 2)), format = "%Y-%m-%d")))
> x
date
1 2002-10-17
2 2002-10-17
3 2002-10-17
4 2002-10-17
5 1999-12-08
6 1999-12-08
> table(x$date)