Displaying 20 results from an estimated 5000 matches similar to: "modifying argument of a .C call (DUP=FALSE)"
2003 Oct 06
1
visualizing transition probability matrices
Dear List,
I have a couple of (~200) 3x3 transition probability matrices (ie each
defines a Markov chain). They are all estimated from the same
underlying process, so it ie meaningful to take their elemetwise mean
and standard deviation. [1]
First question: supposing that they are given in a list l, how do I
get their elementwise mean and standard deviation? Fortunately, the
mean of trans. prob.
1998 Nov 26
1
Saving memory usage -- .C(....., DUP = FALSE) danger?
Just found out [R 0.63, standard -v -n] :
> rm(list=ls())
> gc()
free total
Ncells 96538 200000
Vcells 214008 250000
> hist(runif(50000))
Error: heap memory (1953 Kb) exhausted [needed 390 Kb more]
which is a bit astonishing given that I still have room for 214000 double's
> u1 <- runif(50000)
> u2 <- runif(50000)
> gc()
2010 May 08
1
matrix cross product in R different from cross product in Matlab
Hi all,
I have been searching all sorts of documentation, reference cards, cheat
sheets but can't find why R's
crossprod(A, B) which is identical to A%*%B
does not produce the same as Matlabs
cross(A, B)
Supposedly both calculate the cross product, and say so, or where do I
go wrong?
R is only doing sums in the crossprod however, as indicated by
(z <- crossprod(1:4)) # = sum(1 +
2020 May 01
4
paste(character(0), collapse="", recycle0=FALSE) should be ""
Without 'collapse', 'paste' pastes (concatenates) its arguments elementwise (separated by 'sep', " " by default). New in R devel and R patched, specifying recycle0 = FALSE makes mixing zero-length and nonzero-length arguments results in length zero. The result of paste(n, "th", sep = "", recycle0 = FALSE) always have the same length as
2003 Apr 23
1
Setting up Xemacs + Sweave
Dear list,
I have tried to setup my Xemacs for use with Sweave, which I indend to learn.
I have followed the instructions in the Sweave FAQ, that is to say, I put
(defun Rnw-mode ()
(require 'ess-noweb)
(noweb-mode)
(if (fboundp 'R-mode)
(setq noweb-default-code-mode 'R-mode)))
(add-to-list 'auto-mode-alist '("\\.Rnw\\'" . Rnw-mode))
(add-to-list
2020 May 15
2
paste(character(0), collapse="", recycle0=FALSE) should be ""
Totally agree with that.
H.
On 5/15/20 10:34, William Dunlap via R-devel wrote:
> I agree: paste(collapse="something", ...) should always return a single
> character string, regardless of the value of recycle0. This would be
> similar to when there are no non-NULL arguments to paste; collapse="."
> gives a single empty string and collapse=NULL gives a zero long
2003 Jul 12
2
using cut on matrices
Dear list,
I'd like to use the function cut() on matrices, ie that when I apply
it to a matrix, it would return a matrix of the same dimensions
instead of a vector.
I wonder if there is a better (more elegant) solution than
matrix(cut(a, ...), ncol=ncol(a), nrow=nrow(a))
because I would like to use cut on both vectors and matrices and avoid
testing whether a is a matrix.
Thanks,
Tamas
2004 Jul 05
1
general questions about R on debian/powerpc
Hi,
I am about to but a laptop, and have narrowed the choices down to a
Dell Latitude 600 and an Apple Powerbook G4 Aluminium (Princeton
provides these models at a discount for grad students).
I am biased towards the Powerbook, and would like to run Debian on it.
I have only used debian on i386 platforms so far. I use R quite
frequently, so I would be interested in your experience of running R
2003 Oct 01
3
fitting Markov chains
I need to find a computationally simple process for the movement of
interest rates. In this simplified model, an interest rate can have
3--5 possible values, and its movement is characterized by a matrix of
transition probabilities (ie, it is a Markov process).
I would like to estimate this process from a given set of data.
For example, let the interest rate time series be:
7 3 8 2 5 9 6
2008 Nov 12
2
Outer, kronecker, etc.
`outer` (and related functions like kronecker) require that their
functional argument operate elementwise on arrays. This means for
example that
outer( 1:2, 3:4, list)
or
outer(1:2,3:4,function(a,b){1})
gives an error.
Is there a version of `outer`/`kronecker`/etc. that takes arbitrary
functions and does its own elementwise mapping? In the first example
above, I'd expect the
2011 Feb 07
1
Unusual slowing of R matrix multiplication version 2.12.1 (2010-10-15) vs 2.12.0
R Version 2.12.1 (2010-10-15) vs 2.12.0 has slowed down 8 fold for dual core and 17 fold for dual-core-dual-processor Macs. I have checked this result on 3 different macs using the following R-script:
Using Version 2.12.0 on a dual core dual processor Mac:
> source("http://www.bio.umass.edu/biology/kunkel/pub/R/CuriousResult.R")
matrix multiplication 43.543 1.308 14.788
2004 Apr 10
4
(offtopic) I need two sets of 5 different color scales
Hi,
I am plotting a policy function (result from a dynamic stochastic
optimization problem, discretized approximation). The policy function
maps from an 2 x 2 x 2 x 3 x B x F state space to a B x F state space
(B and F are usually between 4-6, and represent domestic and foreign
savings. The other variables are income (Y), inflation (Pi), domestic
and foreign interest rates (R and Z)). I
2012 Sep 14
4
concatenating two vectors
Dear all,
I want to concatenate the elements of two vectors such as
a<-c("a1","a2")
b<-c("b1","b2")
and obtain
"a1b1", "a1b2","a2b1","a2b2"
I tried the paste and paste0 functions, but they yielded elementwise
concatenation such as
"a1b1","a2b2"
I am wondering that is there an efficient
2008 Nov 06
3
.C(..., DUP=FALSE) memory costs depending on input size?
Hello,
I'm trying to create my own C code for use within R. While optimizing the
code I've noticed that even while only using pointers to get my data to C
the time needed still depends on data (vector) size.
To test this, I've created an empty C function to which I've send vectors
containing various sizes of elements. The time needed for each call is
measured and plotted. I would
2003 Apr 17
1
Testing for whole numbers
Is there a way in R to test if a given number is an integer, ie a
whole number? I am not referring to the data type of a number, but to
its value.
That is to say, is.whole(pi-pi+2) would be TRUE, whereas is.whole(4/3)
would be false. At the moment I am using
is.whole <- function(a) { floor(a)==a }
which is OK for real numbers, but not for complex ones (a+bi would be
a whole number if both a
2000 Sep 26
1
Permutations
Hi,
this is maybe not a real R problem but I want to solve this in R ;-)
Consider the set of all permutations of 1:N (=: S, say) and a fixed
element a from S. I now need to compute the number of permutations s from
S which are elementwise less or equal to a: | { s \in S | s <= a } |
Of cource, backtracking using a tree structure is possible. Does anyone
know an efficient way?
Torsten
2004 May 21
2
Re: Windows versus Unix packages in CRAN ...
Janusz Kawczak wrote:
> You simply need to remove the stuff related to MS Win from zzz.R;
> in partricular the lines after if( .... ) to clear your message.
> As you can see, the info relates to the WinMenu under MS Win.
I think people have been more than a little disingenuous in claiming
that getting the Rmetrics package to go under Linux is transparent.
If you have to dig into the
2000 Sep 07
1
.C and DUP=TRUE versus .Call
Hi Everyone,
I have a piece of C code that uses R_alloc, and so I set DUP=TRUE in the
call using ".C". As I understand it this takes a copy of each object
passed to my function. If these objects are large then this could be
expensive. My question is, if I rewrote the code to use .Call, would I
avoid this duplication by using the objects themselves (they are not
modified in the code)
2000 Mar 20
1
Elementwise c() for lists
I have two lists of equal lengths. Each one consists of vectors. Is
there an elegant way to combine them elementwise? Elegant means: without
loops.
For instance, for
> jja_list(1:3,4:7)
> jjb_list(rep(0,4),(2,5))
I would like to get:
> list(c(1:3,rep(0,4)),c(4:7,rep(2,5))).
--- D.Trenkler ---
************************************************************************
*********
2004 Mar 31
1
extracting values from a 3d array using a matrix from indices
Suppose I have A, an n x m matrix, each element is an integer (an
index).
I also have B, an n x l x m array. I need C, where
C[n,m] = B[n, A[n, m], m]
I am currently using loops, what would be the "R way" to do this?
Another question: let
A[n, m] <- argmax_l B[n, l, m]
what would be the nicest way of doing this? Currently I am using
max.col and a single loop, going though the