similar to: VERY basic question about S4 classes

Displaying 20 results from an estimated 3000 matches similar to: "VERY basic question about S4 classes"

2010 Jul 21
1
fix()ing an S4 method
Hi R experts,   The fix() function canbe used to edit normal functions. I would like to know whether it's also possible to use something similar to edit a method of an S4 class. In other words, is there a fix-like function that allows me to edit method definitions without having to go back to the source code?   setGeneric (name="doStuff",def =
2011 Sep 06
1
list of all methods winthin an S4 class
Hello,   How can I generate an overview/vector of all the methods winthin an S4 class? Similar to dir() in this Python code: >>> class SomeClass():  def some_method_1(self):   pass  def some_method_2(self):   pass   >>> dir(SomeClass) ['__doc__', '__module__', 'some_method_1', 'some_method_2'] >>>   Thanks in advance! Cheers!! Albert-Jan
2010 Apr 25
1
method dispatching vs inheritance/polymorphism (re-post)
Hi, I'm having trouble seeing the added value over functions defined by setGeneric vis-a-vis methods defined by inheritance and polymorphism. setGeneric offers a 'clean' call to a generic function, ie. no need to call new(), so less typing to do for the user. But such explicit calls can also be avoided by functions like f <- function(x, y) new(Class = SomeClass, x=x, y=y). Then
2010 May 20
1
getSubClasses()?
Hi,   Is there a built in function that returns a character vector of all subclasses of a given superclass? showClass(Class = "SomeClass") contains the info that I want, but I don't know how to access it. getSubClasses <- function(superClass) return(setdiff(getClasses(.GlobalEnv), superClass)) wíll only work if the global enviroment isn;t filled with other class definitions.
2010 May 12
1
slot assignment in S4 classes
Hi R friends,   I'm still studying S4 classes and I have a question about slot assignment. Why would I have to use a special setter method [example 2 below] if I can assign data to a slot directly when I call new() [example 1 below]?   ## first way to do it (the idiosyncratic way?) setClass(Class = "TestClass", representation = representation(myDf = "data.frame"))
2011 Aug 25
1
Question about object permanence/marshalling
Hello,   I am trying to write some code that dumps R objects to the harddisk in a binary format so they can be quickly re-used later. Goal is to save time. The objects may be quite large (e.g. classes for a GUI). I was thinking that save() and load() would be suitable for this (until now I only thought it could be used for 'real' data, e.g. matrices, data.frames etc), but I am hoping any
2010 Jul 22
1
check menu button (tcltk)
Hi,   I am making a mock user interface in tcltk and I would like to add a 'check menu button' such as shown here: http://zetcode.com/tutorials/pygtktutorial/images/checkmenuitem.png   Does anybody know how to do this? I am quite new to R. Cheers!! Albert-Jan ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ All right, but apart from the sanitation, the medicine,
2010 Apr 29
1
UpdateLinks = FALSE
Hi,   I'm reading 100s of excel files and many of them contain links to external files (I hate that, but that aside). Every time such a file is opened, a menu pops up asking if I want to update the links. I never want to update the links. I used the macro recorder to see what code would be needed to suppress that message, but to no avail (I tried more variations, but one attempt is shown
2011 May 26
2
NaN, Inf to NA
Hi, I want to recode all Inf and NaN values to NA, but I;m surprised to see the result of the following code. Could anybody enlighten me about this? > df <- data.frame(a=c(NA, NaN, Inf, 1:3)) > df[is.infinite(df) | is.nan(df)] <- NA > df a 1 NA 2 NaN 3 Inf 4 1 5 2 6 3 > Thanks! Cheers!! Albert-Jan
2011 May 26
2
NaN, Inf to NA
Hi, I want to recode all Inf and NaN values to NA, but I;m surprised to see the result of the following code. Could anybody enlighten me about this? > df <- data.frame(a=c(NA, NaN, Inf, 1:3)) > df[is.infinite(df) | is.nan(df)] <- NA > df a 1 NA 2 NaN 3 Inf 4 1 5 2 6 3 > Thanks! Cheers!! Albert-Jan
2011 May 03
1
Rodbc quesion: how to reliably determine the data type?
Hello, How can I tell RODBC to scan all the records of an xls file to determine the data type? If the first n records happen to be empty Rodbc assumes a character, and any numbers are made <NA>. And if, for instance, the first n records contain numbers, and later they also contain characters, those characters become NA. Cheers!! Albert-Jan
2010 Apr 19
1
Equivalent to Python os.walk?
Hi,   I would like to recursively loop through al subfolders of a directory and do stuff with certain file types in those dirs. Is there a package/function that could do this? So it's more than Sys.glob. I'm looking for equivalent of Python's os.walk *) and I don't want to reinvent the wheel.   Thank you. Cheers!! Albert-Jan   *)
2011 Feb 03
1
mapply question (?)
Hi, I have a function myFun which I want to call multiple times, using different argument lists. myFun("v1", "2009", 1) myFun("v2", "2008", 1) myFun("q", "2001") How can I easily do this in R? Should I use mapply? I unsuccessfully tried something like: x <- list(c("v1", "2009", 1), c("v2",
2011 May 31
1
reshape::cast: invalid 'yinds' argument
Hi, I'm using reshape to cast molten data. When I use the following command, R either crashes (when I use Notepad++) or gives an error (when I use Rgui or source()), BUT the error occurs not always, maybe only on half the attempts: w <- cast(v, id + code + productname + year + begin + end + specificDesc + specificDesc2 ~ type) Error in merge.data.frame(data, all.combinations, by =
2007 Jul 25
2
initalizing and checking validity of S4 classes
Dear useRs and wizaRds, I am currently developing a set of functions using S4 classes. On the way I encountered the problem exemplified with the code below. For some reason the 'validity' method does not seem to work, i.e. does not check for errors in the specification of the slots of the defined class. Any hints? My understanding of the whole S4 system was that validity checks are made
2010 Apr 30
1
re.findall equivalent?
Hi, The regular expression (grep) below does not behave at all like the equivalent in Python. Also, I would be happy if somebody could tell me what the R equivalent for Python's re.findall is. The regex filters out any numbers not enclosed by square brackets, including fractions (with either comma or dot as the separator) and percentages. How should the R code below be modified so it does the
2009 Oct 01
1
debugging S4 methods
Hi all, Does anyone know how to debug S4 methods? In my case I want to find an error in the specc-function of the kernlab-package. As this seems to be a S4-method the normal S3 debugging can't be applied apparently (e.g. debug(s3function.someclass)). So in my case > debug(specc:kernlab) seems only to debug the generic-function: > specc:kernlab function (x, ...)
2011 May 04
2
first occurrence of a value?
Hello, A simple question perhaps, but how do I, within each row, find the first occurence of the number 1 in the df below? I want to use this position to programmatically create the variable 'year'. I'v come up with a solution, but I find it downright ugly. Is there a simpler way? I was hoping for a useful built-in function that I don;t yet know about. df <-
2006 Mar 04
2
convert string to AR class
Hi everyone, I''m trying to convert a string passed on the command-line into an ActiveRecord class, so I can do something like this. a="SomeClass" a.find(:all) where class SomeClass < ActiveRecord::Base end This appears to work (better ways would be appreciated): a="SomeClass" b=eval a b.find(:all) However I would like to make sure
2006 Sep 27
1
acts_as_taggable with single-table inheritance?
Does anyone have any experience making this work? I installed the plugin and tried the following: class SomeClass < ActiveRecord::Base acts_as_Taggable end class SubClass1 < SomeClass end class SubClass2 < SomeClass end SubClass1.tag_with("tag") and notice that taggable_type = SomeClass when I do SubClass2.find_tagged_with("tag") a SubClass1 object is