Displaying 20 results from an estimated 10000 matches similar to: "single row/column-indexing on matrices"
2013 Feb 14
3
list of matrices --> array
i'm somehow embarrassed to even ask this, but is there any built-in
method for doing this:
my_list <- list()
my_list[[1]] <- matrix(1:20, ncol = 5)
my_list[[2]] <- matrix(20:1, ncol = 5)
now, knowing that these matrices are identical in dimension, i'd like
to unfold the list to a 2x4x5 (or some other permutation of the dim
sizes) array.
i know i can initialize the array, then
2012 Nov 14
2
vectorized plotmath expressions via substitute()
hi all - i've seen versions of this question before, but none seem to get
directly at my solving my (probably very simple) issue:
i simply want to annotate the tick marks on an axis with (superscripted)
10^x notation, and tried this:
axis(1, at = axTicks(1), as.expression(substitute(10^foo, list(foo =
axTicks(1))))
thinking the as.expression/substitute would create the appropriate
2009 Sep 27
2
dimension-preserving matrix coersion
i've written a function to coerce a matrix (e.g. from numeric to
logical), but i'd like to know if someone has a more elegant method
for this:
> m <- matrix(c(0, 1, 1, 0), ncol = 2)
> m <- as.logical(m)
> m
[1] FALSE TRUE TRUE FALSE
i'd like 'm' to still be a matrix with the original dimensions. in my
function to do this, i coerce 'm' to a logical,
2010 Jul 16
2
aggregate(...) with multiple functions
hi all - i'm just wondering what sort of code people write to
essentially performa an aggregate call, but with different functions
being applied to the various columns.
for example, if i have a data frame x and would like to marginalize by
a factor f for the rows, but apply mean() to col1 and median() to
col2.
if i wanted to apply mean() to both columns, i would call:
aggregate(x, list(f),
2013 Jan 20
2
"user units" in plotrix
hi all - i'm having some difficulty figuring out how to convert
between "user units" (which i can't find a definition for in the
plotrix package) and either (a) device units (e.g. inches with PDFs)
or (b) user coordinates along any particular axis.
as an example, suppose i set up a PDF device with inches, the device
has both outer and inner magins, and the plot region has
2014 Oct 27
1
proper use of reg.finalizer to close connections
Hi all, I have a question about finalizers...
I have a package that manages state for a few connections, and I'd
like to ensure that these connections are 'cleanly' closed upon either
(i) R quitting or (ii) an unloading of the package.
So, in a pared-down example package with a single R file, it looks
something like:
##### BEGIN PACKAGE CODE #####
.CONNS <- new.env(parent =
2009 Sep 15
2
wilcox.test p-value = 0
hi, folks,
how have you gone about reporting a p-value from a test when the
returned value from a test (in this case a rank-sum test) is
numerically equal to 0 according to the machine?
the next lowest value greater than zero that is distinct from zero on
the machine is likely algorithm-dependent (the algorithm of the test
itself), but without knowing the explicit steps of the algorithm
2010 Jun 02
1
ESS (emacs speaks statistics) saving history
hi folks, i use ESS mode in emacs often to interact with R, and while
i know how to save a session transcript, i'm wondering how to save
just the history of the commands (i.e. identically to how R gives the
history save option from its native CLI).
if you use ESS with an R process, commands entered from a separate
buffer and sent to the process do not get registered with the R
history, and
2010 Jul 28
1
specifying an unbalanced mixed-effects model for anova
hi all - i'm having trouble using lme to specify a mixed effects
model.
i'm pretty sure this is quite easy for the experienced anova-er, which
i unfortunately am not.
i have a data frame with the following columns:
col 1 : "Score1" (this is a continuous numeric measure between 0 and
1)
col 2 : "Score2" (another continuous numeric measure, this time
bounded between 0
2006 Jul 06
2
use of apply in a data frame on a row by row basis
Hello all,
I'm trying to use the apply function on a data frame,
by applying a function that takes a one row data.frame as argument .
Here's the example :
myfun = function(x) paste(x$f1 , x$f2)
df = data.frame(f1 = c(1,4,10),f2 = "hello")
apply(df,1,myfun) ==> Does not work (I get "character(0)" )
Though : myfun(df[1,]) works,
and myfun(df) works as well.
So if
2011 May 03
1
bootstrap vignette construction and package installation
hi all - i'm trying to 'R CMD build' a package, but i have what
appears to be a bootstrapping problem:
i've included a vignette in my package, with R code interwoven (and
built using Sweave), but in this documentation i have a code line:
> library(MyPackage)
now, when trying to build a .tar.gz install-able version of my package
in a clean state, i remove the original
2018 Nov 29
4
Unexpected argument-matching when some are missing
When trying out some variations with `[.data.frame` I noticed some (to me) odd behaviour, which I found out has nothing to do with `[.data.frame`, but rather with the way arguments are matched, when mixing named/unnamed and missing/non-missing arguments. Consider the following example:
myfun <- function(x,y,z) {
? print(match.call())
? cat('x=',if(missing(x)) 'missing'
2010 Jul 11
1
difficulty with R expressions in text/legend
hi, i'm trying to prepend some plain (i.e. unevalutated) text to a
typographically evaluated R expression in a legend(...) call.
here's a working legend(...) call that is close to what i'd like
(where x and y are returned from an lm(...) call):
legend("topleft", legend = c(bquote(R^2 == .(summary(x)$r.squared)),
bquote(R^2 == .(summary(y)$r.squared))), fill =
2010 Jun 28
1
advice on package devel with external libs
hi all - i'm working on an R package that makes use of my own shared
library written in C.
but i also am making use of another C-written library.
(my package is for facilitating biological namespace translations via
online (i.e. up-to-date) biological databases.)
problem is, the library i'm using is not a standard library (i.e. i
doubt it will be installed on most users' machines).
i
2010 Oct 04
1
source package build/installation with subdirectory-lib
hi all - i have a source package i'm writing that i'd like to be able
to install with a special library that my R src files rely on.
to be more precise, i have a normal R package directory structure
(i.e. src/ R/ man/ DESCRIPTION NAMESPACE etc.).
i also have another directory here called depPkg, and it has it's own
configure file for the canonical './configure && make
2014 Nov 17
1
common base functions stripping S3 class
Hi all --- this is less a specific question and more general regarding
S3 classes.
I've noticed that quite a few very common default implementations of
generic functions (e.g. `unique`, `[`, `as.data.frame`) strip away
class information.
In some cases, it appears conditionals have been created to re-assign
the class, but only for a few special types.
For example, in `unique.default`, if the
2010 Sep 03
3
S4 Method Signatures
Hello,
If the signature of a method defines which generic it implements then I'm confused about why this minimal example I invented won't work :
setGeneric("myFun", function(rs, ...){standardGeneric("myFun")})
setGeneric("myFun", function(cs, ...){standardGeneric("myFun")})
setMethod("myFun", "numeric", function(rs, colour =
2006 Feb 02
2
How to get the namespace of a function?
I declared the environment of the function myfun to be NULL as follows:
environment(myfun) <- NULL
Later on I called that myfun and got an error message because the
function index() in the zoo package was called inside myfun and was
not visible:
Error in myfun(args) : couldn't find function "index"
I tried to use zoo::index() instead of index(), but that did not work.
In fact,
2011 Feb 02
1
pass nrow(x) to dots in function(x){plot(x,...)}
Dear Rers,
I have a function to barplot() a matrix, eg
myfun <- function(x, ...) { barplot(x , ... )}
(The real function is more complicated, it does things to the matrix first.)
So I can do:
m1 <- matrix(1:20,4)
myfun(m1)
myfun(m1, main="My title")
I'd like to be able to add the number of rows of the matrix passed to
the function to the "..." argument, eg
2009 Jun 12
1
how to trigger variable creation?
Hello R users,
i'm wondering how to trigger variable creation.
Whenever a variable is created i want my own function myFun(...) to be
started.
if (exists("x")) {rm(x)} # after removal of x
# any of these calls
x<-10 # should call myFun
x=10 # should call myFun
assign(x,10) # should call myFun
etc.