Re: [Rd] Why is strptime always returning a vector of length 9 ?
> "l" == laurent
> on Sun, 09 Aug 2009 21:45:07 +0200 writes:
l> Thanks. It seems that the source of my confusion comes
l> from using first using str() (and then once on the wrong
l> track, it is easier to miss the information a man page
l> that also describes POSIXct that is itself a vector of
l> length equal to the number of entries it contains).
l> With the current example:
>> str(xd)
l> POSIXlt[1:9], format: "2007-03-09" "2007-05-31"
l> "2008-11-12" "2008-11-12" ...
l> A quick inspection of the output does indicate a
l> something with nine elements, but the elements appear to
l> be "2007-03-09", "2007-05-31", etc... possibly creating
l> confusion.
l> To make it even more confusing I have:
>> x[1]
l> [1] "March 09, 2007"
>> str(x[1])
l> chr "March 09, 2007"
l> For what it is worth, I think that the behavior of the
l> extract operator "[" (defined as a S3 method
l> "[.POSIXlt()") is inconsistent with the output of
l> length() (default method for lists).
Yes, exactly; these two have beeb defined inconsistently,
exactly in the respect you mention.
Many months ago, when I came to the same conclusion,
I vaguely remember that I had wanted / proposed to change this
(namely, change [.POSIXlt, the length() method for "POSIXlt") ,
but IIRC had been vetoed by others.
... another frustrating experience for me ...
Martin Maechler, ETH Zurich
l> On Sun, 2009-08-09 at 11:45 -0500, Jeff Ryan wrote:
>> The reason is in the ?strptime under value:
>>
>> 'strptime' turns character representations into an object of class
>> '"POSIXlt"'. The timezone is used to set the 'isdst' component
>> and to set the '"tzone"' attribute if 'tz != ""'.
>>
>> And POSIXlt is a list of length 9.
>>
>>
>> HTH
>> Jeff
>>
>> On Sun, Aug 9, 2009 at 10:35 AM, Gabor
>> Grothendieck wrote:
>> > Try this to see its components:
>> >
>> >> str(unclass(xd))
>> > List of 9
>> > $ sec : num [1:6] 0 0 0 0 0 0
>> > $ min : int [1:6] 0 0 0 0 0 0
>> > $ hour : int [1:6] 0 0 0 0 0 0
>> > $ mday : int [1:6] 9 31 12 12 30 30
>> > $ mon : int [1:6] 2 4 10 10 6 6
>> > $ year : int [1:6] 107 107 108 108 109 109
>> > $ wday : int [1:6] 5 4 3 3 4 4
>> > $ yday : int [1:6] 67 150 316 316 210 210
>> > $ isdst: int [1:6] 0 1 0 0 1 1
>> >
>> > and read R News 4/1 for more.
>> >
>> > On Sun, Aug 9, 2009 at 10:20 AM, laurent wrote:
>> >> Dear List,
>> >>
>> >>
>> >> I am having an issue with strptime (see below).
>> >> I can reproduce it on R-2.8, R-2.9, and R-2.10-dev, I tempted to see
>> >> either a bug or my misunderstanding (and then I just don't currently
see
>> >> where).
>> >>
>> >> # setup:
>> >> x <- c("March 09, 2007", "May 31, 2007", "November 12, 2008",
"November
>> >> 12, 2008", "July 30, 2009", "July 30, 2009" )
>> >>
>> >> # showing the problem
>> >>> length(x)
>> >> 6
>> >>> xd <- strptime(x, format = "%B %d, %Y")
>> >>> length(xd)
>> >> 9
>> >>> xd[1:9]
>> >> [1] "2007-03-09" "2007-05-31" "2008-11-12" "2008-11-12" "2009-07-30"
>> >> [6] "2009-07-30" NA NA NA
>> >>> length(strptime(rep(x, 2), format="%B %d, %Y"))
>> >> [1] 9
>> >>> strptime(rep(x, 2), format="%B %d, %Y")[1:12]
>> >> [1] "2007-03-09" "2007-05-31" "2008-11-12" "2008-11-12" "2009-07-30"
>> >> [6] "2009-07-30" "2007-03-09" "2007-05-31" "2008-11-12" "2008-11-12"
>> >> [11] "2009-07-30" "2009-07-30
>> >>
>> >> Any pointer would be appreciated.
>> >>
>> >> L.
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[Rd] model.matrix evaluation challenges
I am having difficulty with evaluation/environment construction for a formula to be evaluated by model.matrix(). Basically, I want to construct a model matrix that first looks in "newdata" for the values of the model parameters, then in "obj...@data". Here's what I've tried: 1. model.matrix(~f,data=c(newdata,obj...@data)) -- fails because something (terms()?) within model.matrix() tries to coerce "data" to a data frame -- but newdata and obj...@data have different numbers of rows. 2. with(c(newdata,obj...@data),model.matrix(~f)) works -- BUT not when ~f is assigned to another object (as it will be when it is being dug out of a previously fit model). 3. If "f" exists as a column within newdata and/or obj...@data, but the formula is assigned to another object (see below), then with(c(newdata,obj...@data),model.matrix(z)) fails -- because model.matrix() is explicitly evaluating the variables in the formula in the environment of z (i.e., ignoring the first argument of "with" ...) Any advice on how to solve this without making a bigger mess? sincerely Ben Bolker ## set up a data frame for prediction set.seed(1001) f = factor(rep(letters[1:4],each=20)) x = runif(80) u = rnorm(4) y = rnorm(80,mean=2+x*(3+u[f]),sd=0.1) dat = data.frame(f,x,y) ## fit a model ... could easily do by lm() but want to ## demonstrate the problem library(bbmle) m1 = mle2(y~dnorm(a+b*x,sd=exp(logs)),parameters=list(b~f),data=dat, start=list(a=0,b=2,logs=-3)) ## data frame for prediction pp0 = expand.grid(x=seq(0,1,length=11), f=levels(dat$f)) ## combine frame and model data: have to keep the model data ## around, because it contain other information needed for ## prediction. cc = c(pp0,m...@data) try(mm <- model.matrix(~f,cc)) ## fails -- different number of rows ## (at some point R tries to coerce cc to a data frame) nrow(with(cc,model.matrix(~f))) ## works ... but ... ## here's what happens within predict.mle2() ## extract information about parameter models params <- eval(m...@call$parameters) params <- params[[1]] params[[2]] <- NULL nrow(with(cc,model.matrix(params))) rm(f) ## object "f" not found -- because model.matrix ## evaluates in the parent environment of params ... try(nrow(with(cc,model.matrix(params -- Ben Bolker Associate professor, Biology Dep't, Univ. of Florida bol...@ufl.edu / www.zoology.ufl.edu/bolker GPG key: www.zoology.ufl.edu/bolker/benbolker-publickey.asc signature.asc Description: OpenPGP digital signature __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
Re: [Rd] Problem using model.frame with argument subset in own function
On Sun, 2009-08-09 at 11:32 -0500, Douglas Bates wrote:
> On Sat, Aug 8, 2009 at 1:31 PM, Gavin Simpson wrote:
> > Dear List,
>
> > I am writing a formula method for a function in a package I maintain. I
> > want the method to return a data.frame that potentially only contains
> > some of the variables in 'data', as specified by the formula.
>
> The usual way to call model.frame (the method that Thomas Lumley has
> called "the standard, non-standard evaluation) is to match the call to
> foo, replace the name of the function being called with
> as.name("model.frame") and force an evaluation in the parent frame.
> it looks like
>
Thanks Doug. I also received an off-list reply from Brian Ripley
suggesting two alternative approaches.
The bit I was missing was how to manipulate other aspects of the call -
it hadn't clicked that the arguments of the function can be manipulated
by altering the components of the matched call.
In the end I came up with something like:
mf <- match.call()
mf[[1]] <- as.name("model.frame")
mt <- terms(formula, data = data, simplify = TRUE)
mf[[2]] <- formula(mt, data = data)
mf$na.action <- substitute(na.action)
dots <- list(...)
mf[[names(dots)]] <- NULL
mf <- eval(mf,parent.frame())
tran.default(mf, ...)
which seems to be working in the tests I have been running, allowing me
to pass along some components of the call to model.frame, whilst
reserving ... for the default methods arguments, and also get the
simplified formula.
All the best,
G
> mf <- match.call()
> if (missing(data)) data <- environment(formula)
> ## evaluate and install the model frame
> m <- match(c("formula", "data", "subset", "weights", "na.action",
> "offset"),
>names(mf), 0)
> mf <- mf[c(1, m)]
> mf$drop.unused.levels <- TRUE
> mf[[1]] <- as.name("model.frame")
> fr <- eval(mf, parent.frame())
>
> The point of all of this manipulation is to achieve the kind of result
> you need where the subset argument is evaluated in the correct
> environmnent.
>
> > The problem I am having is in writing the function and wrapping it
> > around model.frame. Consider the following data frame:
> >
> > dat <- data.frame(A = runif(10), B = runif(10), C = runif(10))
> >
> > And the wrapper function:
> >
> > foo <- function(formula, data = NULL, ..., subset = NULL,
> >na.action = na.pass) {
> >mt <- terms(formula, data = data, simplify = TRUE)
> >mf <- model.frame(formula(mt), data = data, subset = subset,
> > na.action = na.action)
> >## real function would do more stuff here and pass mf on to
> >## other functions
> >mf
> > }
> >
> > This is how I envisage the function being called. The real world use
> > would have a data.frame with tens or hundreds of components where only a
> > few need to be excluded. Hence wanting formulas of the form below to
> > work.
> >
> > foo(~ . - B, data = dat)
> >
> > The aim is to return only columns A and C in an object returned by
> > model.frame. However, when I run the above, I get the following error:
> >
> >> foo(~ A + B, data = dat)
> > Error in xj[i] : invalid subscript type 'closure'
> >
> > I've tracked this down to the line in model.frame.default
> >
> >subset <- eval(substitute(subset), data, env)
> >
> > After evaluating this line, subset contains:
> >
> > Browse[1]> subset
> > function (x, ...)
> > UseMethod("subset")
> >
> >
> > Not NULL, and hence the error later on when calling the internal
> > model.frame code.
> >
> > So the question is, what am I doing wrong?
> >
> > If I leave the subset argument out of the definition of foo and rely
> > upon the default in model.frame.default, the function works as
> > expected.
> >
> > Perhaps the question should be, how do I modify foo() to allow it to
> > have a formal subset argument, passed to model.frame?
> >
> > Any other suggestions gratefully accepted.
> >
> > Thanks in advance,
> >
> > G
> > --
> > %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%
> > Dr. Gavin Simpson [t] +44 (0)20 7679 0522
> > ECRC, UCL Geography, [f] +44 (0)20 7679 0565
> > Pearson Building, [e] gavin.simpsonATNOSPAMucl.ac.uk
> > Gower Street, London [w] http://www.ucl.ac.uk/~ucfagls/
> > UK. WC1E 6BT. [w] http://www.freshwaters.org.uk
> > %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%
> >
> > __
> > R-devel@r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-devel
> >
--
%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%
Dr. Gavin Simpson [t] +44 (0)20 7679 0522
ECRC, UCL Geography, [f] +44 (0)20 7679 0565
Pearson Building, [e] gavin.simpsonATNOSPAMucl.ac.uk
Gower Street, London [w] http://www.ucl.ac.uk/~ucfagls/
UK. WC1E 6BT. [w] http://www.freshwaters.org.uk
%
Re: [Rd] Why is strptime always returning a vector of length 9 ?
Thanks.
It seems that the source of my confusion comes from using first using
str() (and then once on the wrong track, it is easier to miss the
information a man page that also describes POSIXct that is itself a
vector of length equal to the number of entries it contains).
With the current example:
> str(xd)
POSIXlt[1:9], format: "2007-03-09" "2007-05-31" "2008-11-12"
"2008-11-12" ...
A quick inspection of the output does indicate a something with nine
elements, but the elements appear to be "2007-03-09", "2007-05-31",
etc... possibly creating confusion.
To make it even more confusing I have:
> x[1]
[1] "March 09, 2007"
> str(x[1])
chr "March 09, 2007"
For what it is worth, I think that the behavior of the extract operator
"[" (defined as a S3 method "[.POSIXlt()") is inconsistent with the
output of length() (default method for lists).
L.
On Sun, 2009-08-09 at 11:45 -0500, Jeff Ryan wrote:
> The reason is in the ?strptime under value:
>
> 'strptime' turns character representations into an object of class
> '"POSIXlt"'. The timezone is used to set the 'isdst' component
> and to set the '"tzone"' attribute if 'tz != ""'.
>
> And POSIXlt is a list of length 9.
>
>
> HTH
> Jeff
>
> On Sun, Aug 9, 2009 at 10:35 AM, Gabor
> Grothendieck wrote:
> > Try this to see its components:
> >
> >> str(unclass(xd))
> > List of 9
> > $ sec : num [1:6] 0 0 0 0 0 0
> > $ min : int [1:6] 0 0 0 0 0 0
> > $ hour : int [1:6] 0 0 0 0 0 0
> > $ mday : int [1:6] 9 31 12 12 30 30
> > $ mon : int [1:6] 2 4 10 10 6 6
> > $ year : int [1:6] 107 107 108 108 109 109
> > $ wday : int [1:6] 5 4 3 3 4 4
> > $ yday : int [1:6] 67 150 316 316 210 210
> > $ isdst: int [1:6] 0 1 0 0 1 1
> >
> > and read R News 4/1 for more.
> >
> > On Sun, Aug 9, 2009 at 10:20 AM, laurent wrote:
> >> Dear List,
> >>
> >>
> >> I am having an issue with strptime (see below).
> >> I can reproduce it on R-2.8, R-2.9, and R-2.10-dev, I tempted to see
> >> either a bug or my misunderstanding (and then I just don't currently see
> >> where).
> >>
> >> # setup:
> >> x <- c("March 09, 2007", "May 31, 2007", "November 12, 2008", "November
> >> 12, 2008", "July 30, 2009", "July 30, 2009" )
> >>
> >> # showing the problem
> >>> length(x)
> >> 6
> >>> xd <- strptime(x, format = "%B %d, %Y")
> >>> length(xd)
> >> 9
> >>> xd[1:9]
> >> [1] "2007-03-09" "2007-05-31" "2008-11-12" "2008-11-12" "2009-07-30"
> >> [6] "2009-07-30" NA NA NA
> >>> length(strptime(rep(x, 2), format="%B %d, %Y"))
> >> [1] 9
> >>> strptime(rep(x, 2), format="%B %d, %Y")[1:12]
> >> [1] "2007-03-09" "2007-05-31" "2008-11-12" "2008-11-12" "2009-07-30"
> >> [6] "2009-07-30" "2007-03-09" "2007-05-31" "2008-11-12" "2008-11-12"
> >> [11] "2009-07-30" "2009-07-30
> >>
> >> Any pointer would be appreciated.
> >>
> >>
> >>
> >> L.
> >>
> >> __
> >> R-devel@r-project.org mailing list
> >> https://stat.ethz.ch/mailman/listinfo/r-devel
> >>
> >
> > __
> > R-devel@r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-devel
> >
>
>
>
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Re: [Rd] odbcConnectExcel on non-Windows?
Hi Spencer, Unfortunately, the two Perl modules in question, Text::CSV_XS and Encode, are not pure Perl modules as they contain C code. This means that the modules need to be compiled either beforehand as a pre-packaged binary or during installation, both for the Perl version that is installed on the user's system and for the operating system in use. The modules are binary specific to the Perl minor version being used (eg. 5.6 is not compatible with 5.8, which is not compatible with 5.10), which further complicates matters. As a consequence, I cannot include them in the package and reasonably expect them to work for a given Perl version/OS combination. For folks on Windows, there are essentially two options: 1. Install the ActiveState Perl distribution, which includes all required modules, without having to install anything extra. That is the easiest method today. 2. Install Duncan's Perl distribution as included in RTools, which at present does not include at least Text::CSV_XS. If one could convince Duncan to add that module to his offering, it would make that option easier, so as to not require users to separately install the module from CPAN or to install AS Perl. I have cc'd Duncan here to solicit his comments on that. It might also reduce the potential for confusion relative to having more than one Perl installation and dealing with setting $PATH, but that is not an overly complicated issue and why I have the 'perl' argument in the functions. For folks on OSX, there seems to be the potential for Text::CSV_XS to be or not to be installed, possibly depending upon when they got their Mac and what updates have been installed. It was installed on my spring 2009 unibody MBP, but not on Prof. Ripley's MB Air, for example. If it is not, one can install XCode Tools to install a C compiler and then install/compile the module from CPAN or from MacPorts. One can also use the AS Perl installation to achieve the same simple approach as on Windows. On most recent Linux distributions, the modules are either already present with the default Perl install or can be easily installed via the distribution's package management system (eg. yum or apt-get). Of course, AS Perl is also available here as yet another option if for some reason, folks don't want to use their Linux distribution's existing tools. The above information is contained in the package INSTALL file. If things there are unclear, I welcome comments and content that might help to clarify things. Regards, Marc On Aug 9, 2009, at 1:09 PM, spencerg wrote: Dear Marc: In spite of your efforts to help me, I still get an "F" in your "WriteXLS" class. Consider the following: > library(WriteXLS) > help(pac=WriteXLS) > testPerl() Perl found. The following Perl modules were not found on this system: Text::CSV_XS If you have more than one Perl installation, be sure the correct one was used here. Otherwise, please install the missing modules. See the package INSTALL file for more information. ## Might it be feasible to include the required Perl modules with the "WriteXLS" package? Then you would not have to rely on fools like me not knowing how to get the preferred copy of any required Perl modules. On my Windows platform (Vista), I got RODBC to work for "writeFindFn2xls" in the "sos" package. Unfortunately, the "daily checks" on R-Forge failed on non-Windows platforms. When I saw that, I asked R-Devel for help. Dirk suggested I try "WriteXLS"; see below. What do you suggest? If I don't hear an answer, I propose to NOT add "WriteXLS" to the "DESCRIPTION" file but rather to modify the code for "writeFindFn2xls" so that on non-Windows platforms, it tests to see if "WriteXLS" is installed. If no, it will issue an appropriate error message. If it finds "WriteXLS", it will try to use it. However, if you have other suggestions, I'd be pleased to hear them. Best Wishes, Spencer Graves > sessionInfo() R version 2.9.1 (2009-06-26) i386-pc-mingw32 locale: LC_COLLATE=English_United States.1252;LC_CTYPE=English_United States. 1252;LC_MONETARY=English_United States. 1252;LC_NUMERIC=C;LC_TIME=English_United States.1252 attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] sos_1.0-5 brew_1.0-3 WriteXLS_1.8.1 ### Dirk Eddelbuettel wrote: On 9 August 2009 at 12:04, spencerg wrote: | What should I do regarding code to write an Excel file in a | non-Windows platform? [...] | What would you suggest we do about this? [...] | If there is a better way to handle this, I would like to know. http://cran.r-project.org/web/packages/WriteXLS/index.html Portable (in the sense of used by Perl, Python, ... or other scripting engines) solutions have existed for
Re: [Rd] odbcConnectExcel on non-Windows?
Dear Gabor: Good suggestion. I will probably do that if "WriteXLS" is not installed or if it is but "testPerl()" is FALSE. Thanks, Spencer Gabor Grothendieck wrote: Instead of writing out an xls file you could write out a file in any format that Excel can read, e.g. csv, with a suitable renaming of your function. On Sun, Aug 9, 2009 at 1:04 PM, spencerg wrote: Hello: What should I do regarding code to write an Excel file in a non-Windows platform? The "sos" package [new version of "RSiteSearch"] on R-Forge includes "writeFindFn2xls", which starts with "require(RODBC)". The next line calls "odbcConnectExcel". This works under Windows but fails under Linux and MacOS. What would you suggest we do about this? It currently tests (.Platform$OS.type == "windows"); if(FALSE), it issues an error, saying that it only works under Windows. Also, the help page skips those tests if the the platform is not Windows. If there is a better way to handle this, I would like to know. Thanks, Spencer __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
Re: [Rd] odbcConnectExcel on non-Windows?
Dear Marc: In spite of your efforts to help me, I still get an "F" in your "WriteXLS" class. Consider the following: > library(WriteXLS) > help(pac=WriteXLS) > testPerl() Perl found. The following Perl modules were not found on this system: Text::CSV_XS If you have more than one Perl installation, be sure the correct one was used here. Otherwise, please install the missing modules. See the package INSTALL file for more information. ## Might it be feasible to include the required Perl modules with the "WriteXLS" package? Then you would not have to rely on fools like me not knowing how to get the preferred copy of any required Perl modules. On my Windows platform (Vista), I got RODBC to work for "writeFindFn2xls" in the "sos" package. Unfortunately, the "daily checks" on R-Forge failed on non-Windows platforms. When I saw that, I asked R-Devel for help. Dirk suggested I try "WriteXLS"; see below. What do you suggest? If I don't hear an answer, I propose to NOT add "WriteXLS" to the "DESCRIPTION" file but rather to modify the code for "writeFindFn2xls" so that on non-Windows platforms, it tests to see if "WriteXLS" is installed. If no, it will issue an appropriate error message. If it finds "WriteXLS", it will try to use it. However, if you have other suggestions, I'd be pleased to hear them. Best Wishes, Spencer Graves > sessionInfo() R version 2.9.1 (2009-06-26) i386-pc-mingw32 locale: LC_COLLATE=English_United States.1252;LC_CTYPE=English_United States.1252;LC_MONETARY=English_United States.1252;LC_NUMERIC=C;LC_TIME=English_United States.1252 attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] sos_1.0-5 brew_1.0-3 WriteXLS_1.8.1 ### Dirk Eddelbuettel wrote: On 9 August 2009 at 12:04, spencerg wrote: | What should I do regarding code to write an Excel file in a | non-Windows platform? [...] | What would you suggest we do about this? [...] | If there is a better way to handle this, I would like to know. http://cran.r-project.org/web/packages/WriteXLS/index.html Portable (in the sense of used by Perl, Python, ... or other scripting engines) solutions have existed for a dozen years. We have a wrapper to Perl code for a long time too (having been of the initial discussions that lead to Greg's initial read.xls from the gdata package). Dirk __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
Re: [Rd] odbcConnectExcel on non-Windows?
Instead of writing out an xls file you could write out a file in any format that Excel can read, e.g. csv, with a suitable renaming of your function. On Sun, Aug 9, 2009 at 1:04 PM, spencerg wrote: > Hello: > > What should I do regarding code to write an Excel file in a non-Windows > platform? > > The "sos" package [new version of "RSiteSearch"] on R-Forge includes > "writeFindFn2xls", which starts with "require(RODBC)". The next line calls > "odbcConnectExcel". This works under Windows but fails under Linux and > MacOS. > > What would you suggest we do about this? > > It currently tests (.Platform$OS.type == "windows"); if(FALSE), it > issues an error, saying that it only works under Windows. Also, the help > page skips those tests if the the platform is not Windows. > > If there is a better way to handle this, I would like to know. > > Thanks, > Spencer > > __ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel > __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
Re: [Rd] odbcConnectExcel on non-Windows?
On 9 August 2009 at 12:04, spencerg wrote: | What should I do regarding code to write an Excel file in a | non-Windows platform? [...] | What would you suggest we do about this? [...] | If there is a better way to handle this, I would like to know. http://cran.r-project.org/web/packages/WriteXLS/index.html Portable (in the sense of used by Perl, Python, ... or other scripting engines) solutions have existed for a dozen years. We have a wrapper to Perl code for a long time too (having been of the initial discussions that lead to Greg's initial read.xls from the gdata package). Dirk -- Three out of two people have difficulties with fractions. __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
[Rd] odbcConnectExcel on non-Windows?
Hello: What should I do regarding code to write an Excel file in a non-Windows platform? The "sos" package [new version of "RSiteSearch"] on R-Forge includes "writeFindFn2xls", which starts with "require(RODBC)". The next line calls "odbcConnectExcel". This works under Windows but fails under Linux and MacOS. What would you suggest we do about this? It currently tests (.Platform$OS.type == "windows"); if(FALSE), it issues an error, saying that it only works under Windows. Also, the help page skips those tests if the the platform is not Windows. If there is a better way to handle this, I would like to know. Thanks, Spencer __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
Re: [Rd] Why is strptime always returning a vector of length 9 ?
The reason is in the ?strptime under value:
'strptime' turns character representations into an object of class
'"POSIXlt"'. The timezone is used to set the 'isdst' component
and to set the '"tzone"' attribute if 'tz != ""'.
And POSIXlt is a list of length 9.
HTH
Jeff
On Sun, Aug 9, 2009 at 10:35 AM, Gabor
Grothendieck wrote:
> Try this to see its components:
>
>> str(unclass(xd))
> List of 9
> $ sec : num [1:6] 0 0 0 0 0 0
> $ min : int [1:6] 0 0 0 0 0 0
> $ hour : int [1:6] 0 0 0 0 0 0
> $ mday : int [1:6] 9 31 12 12 30 30
> $ mon : int [1:6] 2 4 10 10 6 6
> $ year : int [1:6] 107 107 108 108 109 109
> $ wday : int [1:6] 5 4 3 3 4 4
> $ yday : int [1:6] 67 150 316 316 210 210
> $ isdst: int [1:6] 0 1 0 0 1 1
>
> and read R News 4/1 for more.
>
> On Sun, Aug 9, 2009 at 10:20 AM, laurent wrote:
>> Dear List,
>>
>>
>> I am having an issue with strptime (see below).
>> I can reproduce it on R-2.8, R-2.9, and R-2.10-dev, I tempted to see
>> either a bug or my misunderstanding (and then I just don't currently see
>> where).
>>
>> # setup:
>> x <- c("March 09, 2007", "May 31, 2007", "November 12, 2008", "November
>> 12, 2008", "July 30, 2009", "July 30, 2009" )
>>
>> # showing the problem
>>> length(x)
>> 6
>>> xd <- strptime(x, format = "%B %d, %Y")
>>> length(xd)
>> 9
>>> xd[1:9]
>> [1] "2007-03-09" "2007-05-31" "2008-11-12" "2008-11-12" "2009-07-30"
>> [6] "2009-07-30" NA NA NA
>>> length(strptime(rep(x, 2), format="%B %d, %Y"))
>> [1] 9
>>> strptime(rep(x, 2), format="%B %d, %Y")[1:12]
>> [1] "2007-03-09" "2007-05-31" "2008-11-12" "2008-11-12" "2009-07-30"
>> [6] "2009-07-30" "2007-03-09" "2007-05-31" "2008-11-12" "2008-11-12"
>> [11] "2009-07-30" "2009-07-30
>>
>> Any pointer would be appreciated.
>>
>>
>>
>> L.
>>
>> __
>> R-devel@r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>
>
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--
Jeffrey Ryan
jeffrey.r...@insightalgo.com
ia: insight algorithmics
www.insightalgo.com
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Re: [Rd] Problem using model.frame with argument subset in own function
On Sat, Aug 8, 2009 at 1:31 PM, Gavin Simpson wrote:
> Dear List,
> I am writing a formula method for a function in a package I maintain. I
> want the method to return a data.frame that potentially only contains
> some of the variables in 'data', as specified by the formula.
The usual way to call model.frame (the method that Thomas Lumley has
called "the standard, non-standard evaluation) is to match the call to
foo, replace the name of the function being called with
as.name("model.frame") and force an evaluation in the parent frame.
it looks like
mf <- match.call()
if (missing(data)) data <- environment(formula)
## evaluate and install the model frame
m <- match(c("formula", "data", "subset", "weights", "na.action", "offset"),
names(mf), 0)
mf <- mf[c(1, m)]
mf$drop.unused.levels <- TRUE
mf[[1]] <- as.name("model.frame")
fr <- eval(mf, parent.frame())
The point of all of this manipulation is to achieve the kind of result
you need where the subset argument is evaluated in the correct
environmnent.
> The problem I am having is in writing the function and wrapping it
> around model.frame. Consider the following data frame:
>
> dat <- data.frame(A = runif(10), B = runif(10), C = runif(10))
>
> And the wrapper function:
>
> foo <- function(formula, data = NULL, ..., subset = NULL,
> na.action = na.pass) {
> mt <- terms(formula, data = data, simplify = TRUE)
> mf <- model.frame(formula(mt), data = data, subset = subset,
> na.action = na.action)
> ## real function would do more stuff here and pass mf on to
> ## other functions
> mf
> }
>
> This is how I envisage the function being called. The real world use
> would have a data.frame with tens or hundreds of components where only a
> few need to be excluded. Hence wanting formulas of the form below to
> work.
>
> foo(~ . - B, data = dat)
>
> The aim is to return only columns A and C in an object returned by
> model.frame. However, when I run the above, I get the following error:
>
>> foo(~ A + B, data = dat)
> Error in xj[i] : invalid subscript type 'closure'
>
> I've tracked this down to the line in model.frame.default
>
> subset <- eval(substitute(subset), data, env)
>
> After evaluating this line, subset contains:
>
> Browse[1]> subset
> function (x, ...)
> UseMethod("subset")
>
>
> Not NULL, and hence the error later on when calling the internal
> model.frame code.
>
> So the question is, what am I doing wrong?
>
> If I leave the subset argument out of the definition of foo and rely
> upon the default in model.frame.default, the function works as
> expected.
>
> Perhaps the question should be, how do I modify foo() to allow it to
> have a formal subset argument, passed to model.frame?
>
> Any other suggestions gratefully accepted.
>
> Thanks in advance,
>
> G
> --
> %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%
> Dr. Gavin Simpson [t] +44 (0)20 7679 0522
> ECRC, UCL Geography, [f] +44 (0)20 7679 0565
> Pearson Building, [e] gavin.simpsonATNOSPAMucl.ac.uk
> Gower Street, London [w] http://www.ucl.ac.uk/~ucfagls/
> UK. WC1E 6BT. [w] http://www.freshwaters.org.uk
> %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%
>
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Re: [Rd] Why is strptime always returning a vector of length 9 ?
Try this to see its components:
> str(unclass(xd))
List of 9
$ sec : num [1:6] 0 0 0 0 0 0
$ min : int [1:6] 0 0 0 0 0 0
$ hour : int [1:6] 0 0 0 0 0 0
$ mday : int [1:6] 9 31 12 12 30 30
$ mon : int [1:6] 2 4 10 10 6 6
$ year : int [1:6] 107 107 108 108 109 109
$ wday : int [1:6] 5 4 3 3 4 4
$ yday : int [1:6] 67 150 316 316 210 210
$ isdst: int [1:6] 0 1 0 0 1 1
and read R News 4/1 for more.
On Sun, Aug 9, 2009 at 10:20 AM, laurent wrote:
> Dear List,
>
>
> I am having an issue with strptime (see below).
> I can reproduce it on R-2.8, R-2.9, and R-2.10-dev, I tempted to see
> either a bug or my misunderstanding (and then I just don't currently see
> where).
>
> # setup:
> x <- c("March 09, 2007", "May 31, 2007", "November 12, 2008", "November
> 12, 2008", "July 30, 2009", "July 30, 2009" )
>
> # showing the problem
>> length(x)
> 6
>> xd <- strptime(x, format = "%B %d, %Y")
>> length(xd)
> 9
>> xd[1:9]
> [1] "2007-03-09" "2007-05-31" "2008-11-12" "2008-11-12" "2009-07-30"
> [6] "2009-07-30" NA NA NA
>> length(strptime(rep(x, 2), format="%B %d, %Y"))
> [1] 9
>> strptime(rep(x, 2), format="%B %d, %Y")[1:12]
> [1] "2007-03-09" "2007-05-31" "2008-11-12" "2008-11-12" "2009-07-30"
> [6] "2009-07-30" "2007-03-09" "2007-05-31" "2008-11-12" "2008-11-12"
> [11] "2009-07-30" "2009-07-30
>
> Any pointer would be appreciated.
>
>
>
> L.
>
> __
> R-devel@r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>
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[Rd] Why is strptime always returning a vector of length 9 ?
Dear List,
I am having an issue with strptime (see below).
I can reproduce it on R-2.8, R-2.9, and R-2.10-dev, I tempted to see
either a bug or my misunderstanding (and then I just don't currently see
where).
# setup:
x <- c("March 09, 2007", "May 31, 2007", "November 12, 2008", "November
12, 2008", "July 30, 2009", "July 30, 2009" )
# showing the problem
> length(x)
6
> xd <- strptime(x, format = "%B %d, %Y")
> length(xd)
9
> xd[1:9]
[1] "2007-03-09" "2007-05-31" "2008-11-12" "2008-11-12" "2009-07-30"
[6] "2009-07-30" NA NA NA
> length(strptime(rep(x, 2), format="%B %d, %Y"))
[1] 9
> strptime(rep(x, 2), format="%B %d, %Y")[1:12]
[1] "2007-03-09" "2007-05-31" "2008-11-12" "2008-11-12" "2009-07-30"
[6] "2009-07-30" "2007-03-09" "2007-05-31" "2008-11-12" "2008-11-12"
[11] "2009-07-30" "2009-07-30
Any pointer would be appreciated.
L.
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