Displaying 20 results from an estimated 4000 matches similar to: "dimension-preserving matrix coersion"
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
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 =
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
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
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
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
2009 Jul 24
1
single row/column-indexing on matrices
hi all - quick question:
i have a matrix m, say nrow=5, ncol=4.
in a function i'd like to retrieve certain rows or columns from m, but
which rows/cols are not known ahead of time.
the function should return a sub-matrix (i.e. still of class
'matrix').
when selecting a single column (or row), the indexing operation
converts the object of class 'matrix' into a vector of
2005 Jan 06
1
Calculating a table of symbol frequencies
Hello all:
I have a protein sequence alignment in a data frame (align1, 72 x 236),
where each row is a protein and each column a site in the alignment. AA is
vector of amino acid symbols plus "-" (gap). I can calculate amino acid
frequencies at each site by:
>align1.F <- matrix(0,nrow=22,ncol=236,dimnames=list(AA,seq(1:236)))
>for(i in 1:236)
>
2009 Nov 11
1
fitting a glm with matrix of responses
hi all - quick question:
i have a matrix 'y' of response values, with two explanatory variables
'x1' and 'x2'.
tested values of 'x1' and 'x2' are sitting in two vectors 'x1' and
'x2'.
i want to learn model parameters without "unrolling" the matrix of
response values.
example below:
# some fake data for the example
x1 <- 1:5
x2
2002 Jan 08
6
Subsets without NA
Is there a way of removing all rows with missing values from a data frame?
I usually use
subset(x, var1!="NA")
and repeat for each variable. It would be nice to be able to do it in one
fell swoop. Also, surprisingly, it doesn't always work. Sometimes I'm left
with an empty set even though not all rows have missing values for the
variable.
Cheers,
mikkel
Mikkel Grum,
2010 Jan 26
1
library.dynam
hi, i'm having some trouble getting a package to load a shared library
object in .onLoad(...)
i have a shared object file, say "mylib.so".
if i start an R session, and via the CLI specify the actual library
via:
> dyn.load("mylib.so")
everything works quite well (i.e. i can then follow with some .Call
(...) methods)
now, i'd like to include this shared library in
2004 Aug 16
1
turning off automatic coersion from list to matrix
Hello,
I am having trouble understanding how R is coercing between matrices and
lists in the following example. I have an aggregate behavior I like:
aggregate(a[,"num"],by=list(product=a[,"product"],region=a[,"region"]),
sum)
Now in reality I have more columns than just product and region, and
need to pick different combinations. So I want to abstract this into a
2010 Jan 29
1
shared object location
hi all, i posted a question before about this, but i may have been too
cryptic to understand.
in short, there exists an R package that someone is writing. this
package depends on a custom library (written in C,), compiled as a
shared, and called by the package's functions via the .Call(...)
method.
we are testing out different code implementations of the compiled
library functions, and thus