Displaying 20 results from an estimated 1000 matches similar to: "apologies (was RE: [R] ISOdate() and strptime())"
2003 Nov 25
0
AW: ISOdate() and strptime()
Thanks for this clarification.
I have learned in the meantime that it is necessary to be very careful when
using all these POSIX things.
As another example, here is something that made me scratch my head just
yesterday:
When I create a sequence of days that happens to start before and ends in
daylight savings time, I seem to lose a day:
> seq(from = strptime("20030329",
2003 Nov 14
5
ISOdate() and strptime()
Dear R-people!
I am using R 1.8.0, under Windows XP.
While using ISOdate() and strptime(), I noticed the following behaviour when
"wrong" arguments (e.g., months>12) are given to these functions:
> ISOdate(year=2003,month=2,day=20) #ok
[1] "2003-02-20 13:00:00 Westeurop?ische Normalzeit"
> ISOdate(year=2003,month=2,day=30) #wrong day, but returns a value
[1]
2004 Feb 06
1
0.1 + 0.2 != 0.3 revisited
Prompted by Peter Dalgard's recent elegant "intbin" function,
I have been playing with the extension to converting reals to binary
representation. The decimal part can be done like this:
decbase <- function(x, n=52, base=2) {
if(n) {
x <- x*base
paste(trunc(x), decbase(x%%1, n-1, base), sep="")
}
}
n=52 default because that's the number of bits in
2004 Aug 31
2
I've forgotten, why is box("") the default?
I've searched on CRAN for axes, axis, and other terms
I've already forgotten, without (re)discovering the
reason for S using "non-joining" axes by default, instead
of box("l").
MASS points me towards Cleveland (1993) but I don't
have ready access to this any more. Could someone
give me a one-liner to justify this choice to a sceptic?
It's something to do
2003 May 28
2
Numbers that look equal, should be equal, but if() doesn'tsee as equal (repost with code included)
Try the following function (the name is supposed to be a joke, by the
way),
which will also do the right thing with NAs and characters. Use it as
if(equal.enough(x,y)) rather than if(x==y), e.g.
> equal.enough(0.1+0.2, 0.3)
[1] TRUE
My default of 15 significant figures may be overkill in many
applications; be
prepared to reduce this.
Simon Fear
"equal.enough" <- function(x, y,
2003 Nov 18
4
address for bug reports? (PR#5171)
bug.report() tells me to email to r-bugs@r-project.org, whereas
the Web site http://www.r-project.org/ points me to
r-bugs@biostat.ku.dk.
Which should I believe?
Simon Fear
Senior Statistician
Syne qua non Ltd
Tel: +44 (0) 1379 644449
Fax: +44 (0) 1379 644445
email: Simon.Fear@synequanon.com
web: http://www.synequanon.com
Number of attachments included with this message: 0
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2003 Sep 17
0
Just don't do it, surely? (was RE: Retrieve ... argument values)
Thanks for the insight.
> -----Original Message-----
> From: Prof Brian Ripley [mailto:ripley at stats.ox.ac.uk]
<snip>
> dots <- list(...)
> haveYlim <- "ylim" %in% names(dots)
>
> is the sort of thing we still understand 5 years later.
>
I didn't say "understand", I said "easily follow". Obviously how
"easily" is
2003 Oct 08
1
is.na(v)<-b (was: Re: Beginner's query - segmentation fault)
Note this behaviour:
> a<-"a"
> a<-NA
> mode(a)
[1] "logical"
> a<-"a"
> is.na(a) <- T
> mode(a)
[1] "character"
However after either way of assigning NA to a, is.na(a) is true,
and it prints as NA, so I can't see it's ever likely to matter. [Why
do I say these things? Expect usual flood of examples where it
does
2003 Oct 08
0
is.na(v)<-b (was: Re: Beginner's query - segmentation fault)
Well, that's a convincing argument, but maybe
it's the name that's worrying some of us. Maybe it would be
more intuitive if called set.na (sorry, I mean setNA).
Also "is.na<-" cannot be used to create a new variable of
NAs, so is not a universal method, which is a shame for its
advocates.
I note also that for a vector you can assign a new NA using
either TRUE or
2003 Oct 09
1
is.na(v)<-b (was: Re: Beginner's query - segmentation fault)
> -----Original Message-----
> From: Richard A. O'Keefe [mailto:ok at cs.otago.ac.nz]
<snip>
> The very existence of an "is.na<-" which accepts a logical
> vector containing FALSE as well as TRUE ...
And don't forget this is not the only usage of is.na<-. In fact it is
designed to take any valid indexing value. For example:
> a<-1:10
>
2003 Jun 11
2
scan() crash in Windows 98 (PR#3234)
# Your mailer is set to "none" (default on Windows),
# hence we cannot send the bug report directly from R.
# Please copy the bug report (after finishing it) to
# your favorite email program and send it to
#
# r-bugs@r-project.org
#
######################################################
scan() (and so also of course read.table, read.csv etc) crashes right
out of
R (GUI)
if it
2003 Oct 15
1
is.na(v)<-b (was: Re: Beginner's query - segmentation fault)
I think the thread ended up with several people (not only me)
feeling certain they didn't like `is.na<-` but with the
developers defending it and me not really understanding
why.
Uwe Ligges was going to come up with an example of
`<- NA` going wrong (sorry Brian R, I mean behaving
unexpectedly), but never did, and I think the problem
has been fixed. It was apparently a problem with
2003 Nov 18
3
plot, plot, methods, crash (PR#5173)
(If this only happens in Win 98, I'm sure I could live with it. Just
may be helpful to report it, I hope.)
Start up R GUI, then
> plot(1:4,1:4) # then close manually by clicking X
> plot(1:4,1:4) # ditto
> methods(plot)
sometimes produces normal output and even the following prompt,
but then crashes immediately, or more often, crashes immediately with
no output.
I can do any
2003 Sep 17
1
Just don't do it, surely? (was RE: Retrieve ... argument values)
Tony, I don't understand what you mean. Could you give
an example?
> -----Original Message-----
> From: Tony Plate [mailto:tplate at blackmesacapital.com]
> > ... I'm not saying "never write functions that use ...",
> >I'm just saying "never write functions that depend on a particular
> >argument being passed via ...".
>
> Several
2003 Aug 12
3
grep and gsub on backslash and quotes
The following code works, to gsub single quotes to double quotes:
line <- gsub("'", '"', line)
(that's a single quote within doubles then a double within singles if
your
viewer's font is not good).
But The R Language Manual tells me that
Quotes and other special characters within strings
are specified using escape sequences:
\' single quote
\"
2003 Aug 27
3
seeking help with with()
I tried to define a function like:
fnx <- function(x, by.vars=Month)
print(by(x, by.vars, summary))
But this doesn't work (does not find x$Month; unlike other functions,
such as
subset(), the INDICES argument to "by" does not look for variables in
dataset
x. Is fully documented, but I forget every time). So I tried using
"with":
fnxx <- function(x, by.vars=Month)
2003 Sep 17
2
Just don't do it, surely? (was RE: Retrieve ... argument values)
There have been various elegant solutions to test for the presence
of a particular named parameter within a ... argument, such as
if (!is.null(list(...)$ylim))
if ("ylim" %in% names(list(...)))
I think I'd have to comment these lines pretty clearly if I wanted
to easily follow the code in 6 months time.
But I'm still not convinced it is ever a good idea to use this
technique
2003 Aug 12
8
capturing output from Win 98 shell
How can I best achieve the following (works in Splus):
filenames <- dos("dir *.sasb7dat /b")
What I am asking, more generically, is: how can I capture the output of
a
DOS command in R?
I have tried using
system("COMMAND.COM /c dir /b", intern=T, show.output.on.console=T)
where
intern: a logical, indicates whether to make the output of the
command an R
2004 Mar 05
1
row-echelon form (was no subject)
I think one needs an LU decomposition rather than QR.
However, I couldn't find anything off the shelf to do
an LU, other than learning that determinant() now
uses LU instead of QR or SVD, so the code to do it must
be in there for those that want it.
You'll probably need to divide rows of U by the first
entry if you insist on the unique reduced REF.
However, I can't see any reason
2003 Nov 19
5
ISOdate returns incorrect date?
Dear all,
I have found the following (for me) incomprehensible behaviour of
ISOdate (POSIXct):
> ISOdate(1900,6,16)
[1] "1900-06-15 14:00:00 Westeurop?ische Sommerzeit"
> ISOdate(1950,6,16)
[1] "1950-06-16 14:00:00 Westeurop?ische Sommerzeit"
Note that in the first case I get the 15th of June back, not the 16th as
I would have expected!
This happened under R-1.7.1 on