similar to: data frame with nested data frame

Hi, I am having a problem to understand why as.data.frame method doesn't dispatch properly on my class: > setClass("Foo", "character") [1] "Foo" > as.data.frame(list(foo=new("Foo", .Data="a"))) Error in as.data.frame.default(x[[i]], optional = TRUE) : can't coerce Foo into a data.frame I was expecting that this would call

Hi, I tried to write the dim method for the list class, but R doesn't seem to dispatch to it: > dim.list = function(x) c(length(x[[1]]), length(x)) > dim(list(1)) NULL > dim.list(list(1)) [1] 1 1 What is the correct way of registering dim.list with .Primitive("dim")? Thanks, Vadim [[alternative HTML version deleted]]

Dear R users, As substitute() help page points out: Substituting and quoting often causes confusion when the argument is 'expression(...)'. The result is a call to the 'expression' constructor function and needs to be evaluated with 'eval' to give the actual expression object. And indeed I am confused. Consider: > dat <- data.frame(x=1:10,

Dear R users, As substitute() help page points out: Substituting and quoting often causes confusion when the argument is 'expression(...)'. The result is a call to the 'expression' constructor function and needs to be evaluated with 'eval' to give the actual expression object. And indeed I am confused. Consider: > dat <- data.frame(x=1:10,

Hi, I thought it would be convenient if the check.names argument to read.table, which currently can only be TRUE/FALSE, could take a function value as well. If the function is supplied it should be used instead of the default make.names. Here is an example where it can come in handy. I tend to keep my data in coma-separated files with a header line. The header line is prefixed with a comment

Hi, Encouraged by a tip from Simon Urbanek I tried to use the S3 machinery to write a faster version of the data.frame class. This quickly hits a snag: the "[.default"(x, i) for some reason cares about the dimensionality of x. In the end there is a full transcript of my R session. It includes the motivation for writing the class and the problems I have encountered. As a result I see

Hi, Is it possible to modify an object in the parent.env (as opposed to re-bind)? Here is what I tried: > x = 1:3 # try to modify the first element of x from within a new environment > local(get("x", parent.env(environment()))[1] <- NA) Error in eval(expr, envir, enclos) : Target of assignment expands to non-language object # On the other hand retrieval works just fine >

Hi, This is not an R question per ce, but I feel like this is a right community to ask it. As a part of our work we run a lot of non-interactive computational jobs. To increase the throughput we would like to distribute the load over the entire network and we are looking at Linux network as a platform. Ideally we would like to be able to submit a job to the network, rather than to a computer, and

Hi, As was discussed earlier in another thread and as documented in R-exts .Call() should not be interruptible by Ctrl-C. However the following code, which spends most of its time inside mkChar, turned out to be interruptible on RH-7.3 R-1.8.1 gcc-2.96: #include <Rinternals.h> #include <R.h> SEXP foo0(const SEXP nSexp) { int i, n; SEXP resSexp; if (!isInteger(nSexp))

Hi, I am looking for an efficient way of skipping big chunks of lines on a connection (not necessarily at the beginning of the file). One way is to use read lines, e.g. readLines(1e6), but a) this incurs the overhead of construction of the return char vector and b) has a (fairly remote) potential to blow up the memory. Another way would be to use scan(), e.g. scan(con, skip=1e6, nmax=0)

Hi, I am trying to figure a way to allocate a string SEXP so that gc() won't ever collect it. Here is a little bit of a background. Suppose I want to write a .Call-callable function that upon each call returns the same value, say mkChar("foo"): SEXP getFoo() { return mkChar("foo"); } The above implementation doesn't take advantage of the fact that

Hi, What is the reason for seq.Date to require the 'by' argument and not to default it to 1 in the example below? > seq(from=as.Date("1996-01-01"), to=as.Date("1996-12-01")) Error in seq.Date(from = as.Date("1996-01-01"), to = as.Date("1996-12-01")) : exactly two of `to', `by' and `length.out' / `along.with' must be specified

Dear R-Users, I need to find a smooth function f() and coefficients a_i that give the best fit to y ~ a_0 + a_1*f(x_1) + a_2*f(x_2) Note that it is the same non-linear transformation f() that is applied to both x_1 and x_2. So my first question is how can I do it in R? A more general question is this: suppose I have a utility function U(a_i, f()), where f() is say a spline. Is there a general

Hi, As far as I can tell data.frame class adds two features to those of lists: * matrix structure via [,] and [,]<- operators (well, I know these are actually "["(i, j, ...), not "[,]"). * row names attribute. It seems that the overhead of the support for the row names, both computational and RAM-wise, is rather non-trivial. I frequently subscript from a data.frame,

Well, "integer" is also a storage.mode in R. It is not immediately clear which meaning the help page uses. I guess some extra elaboration would be helpful. Anyway, thank you for the clarification, Vadim > -----Original Message----- > From: Prof Brian Ripley [mailto:ripley@stats.ox.ac.uk] > Sent: Tuesday, March 22, 2005 9:54 AM > To: Vadim Ogranovich > Cc:

Hi, I have two data sources. One records time in PST time zone, the other in GMT. I want to compute the difference between the two, but don't see how. Here is an example where I compute time difference between identical times each (meant to be) relative to its time zone. > as.POSIXlt("2000-05-10 10:15:00", "PST") - as.POSIXlt("2000-05-10 10:15:00",

Hi, To speed up reading of large (few million lines) CSV files I am writing custom read functions (in C). By timing various approaches I figured out that one of the bottlenecks in reading character fields is the mkChar() function which on each call incurs a lot of garbage-collection-related overhead. I wonder if there is a "vectorized" version of mkChar, say mkChar2(char **, int

Hi, It seems that a formal function argument can not default to an "outer" variable of the same name: > x <- "foo" > ff <- function(x=x) x > ff() Error in ff() : recursive default argument reference > Is this intentional? Why? I use R-1.9.1. Thanks, Vadim

Dear R-devel, The following line crashes R > approx(1, 1, 0, method='const', rule=2, f=0, yleft=NULL, ties='ordered')$y Process R:2 exited abnormally with code 5 at Tue Jul 21 14:18:09 2009 > version _ platform i386-pc-mingw32 arch i386 os mingw32 system i386, mingw32 status major 2 minor 9.1 year

Hi, recover() sends all its messages, which I consider to be error messages, to stdout. I think they more properly belong to stderr. This is an important difference for those of us who use R in batch mode to generate ASCII files. Thanks, Vadim [[alternative HTML version deleted]]