Displaying 20 results from an estimated 6000 matches similar to: "general questions about R on debian/powerpc"
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
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 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
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
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.
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
2004 Apr 26
1
need settings for the listings package
Hi,
I am typesetting R code in TeX using the listings package. I have
experimented with various settings for the text, but all look a bit
ugly. This might be because I have no typographic experience ;-)
I would really appreciate if people sent me the settings they use for
the listings package (eg in the \usepackage line, or \lstset, I am
thinking about choices for basicstyle, ... etc). I
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
2004 Apr 21
2
resetting the interpreter
Hi,
Sometimes I want to "reset" the R interpreter (as if I quit and
started it again, with everything starting from scratch). The main
reason for this is when I expreriment with calculations, and later
form them into general functions, sometimes I forget to include
variables or reset some settings which I don't notice because they are
already set. This causes problems during batch
2004 Apr 25
7
R vs Matlab: which is more "programmer friendly"?
Hi,
The department of economics at our university (Budapest) is planning a
course on numerical methods in economics. They are trying to decide
which software to use for that, and I would like to advocate R. The
other alternative is Matlab.
I have found comparisons in terms of computational time for matrix
algebra, but I don't think that is relevant: the bottleneck for
economists is usually
2004 Apr 27
5
parsing a data file
Hi,
I need to parse a data file (output of a measuring device) of the
following format:
BEGIN RECORD [first record data] RECORD [second
record data] RECORD
[third record data]
END
Line breaks can (and do ;-() occur anywhere. White space behaves very
much like TeX, eg it is not important whether there are one or more
spaces or linebreaks as long as there is one of them. It is a text
file, not
2004 Apr 02
2
"(de)linearizing" array indices
Hi,
I have a dynamic programming problem with many state variables, let's
call them l, n, m, etc. The transition probabilities are originally
given in an array form, eg
transtition[l,m,n,ll,mm,nn]
give the probability of going from l,m,n to ll,mm,nn.
However, the numerical solution is best handled when I "flatten" the L
x M x N state space into a single one (call it S), ie a
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
2005 Aug 13
1
retrieving large columns using RODBC
Hi,
I have a large table in Postgresql (result of an MCMC simulation, with 1
million rows) and I would like to retrive colums (correspond to variables)
using RODBC. I have a column called "index" which is used to order rows.
Unfortunately, sqlQuery can't return all the values from a column at once
(RODBC complains about lack of memory). So I am using the following code:
2004 Apr 07
1
eigenvalues for a sparse matrix
Hi,
I have the following problem. It has two parts.
1. I need to calculate the stationary probabilities of a Markov chain,
eg if the transition matrix is P, I need x such that
xP = x
in other words, the left eigenvectors of P which have an eigenvalue of
one.
Currently I am using eigen(t(P)) and then pick out the vectors I need.
However, this seems to be an overkill (I only need a single
2004 Mar 31
2
array addition doesn't recycle!
Hi,
I have noticed the following:
> a <- array(1:4, c(2, 2))
> A <- array(1:4, c(2,2,2))
> A + a
Error in A + a : non-conformable arrays
It works with a matrix + a vector, why doesn't it work with arrays?
Am I missing something?
How would you do the above operation efficiently (ie I need to add a
matrix to each "plane" of 3-dim array)? At the moment I am using
2003 Apr 05
3
slides in linux R
Hello,
In S-Plus Windows you can transform graphics to Powerpoint very easily, in R Windows you can use enhanced metafiles (.emf) and Powerpoint almost as easy. Is there a simular way with R in Linux to transform to the presentation program in StarOffice or OpenOffice or are you stuck with the pdf device?
Fredrik Lundgren
2004 May 25
4
Object "silhouette.default" not found. But I knew that it is there.
Hi!
>library(cluster)
In this lib a function called silhoutte.default is defined
than on the R prompt it type
>silhouette.default
Error: Object "silhouette.default" not found
R1.9.0
The same error are at R1.8.1
And I knew that a function silhoutte.default are present.
But the same piece of code works in R1.6.2
???
Eryk
Dipl. bio-chem. Eryk Witold Wolski @
2003 Apr 30
2
Working comfortably with (X)Emacs + Sweave
Dear List,
I am trying to become more familiar with Sweave at the moment, beacuse
I am convinced that it will eventually make my life easier. However,
I have not found anything relevant in the mail archives about the
following problem.
Both the article in R-News and the Sweave FAQ suggest that Emacs would
be a great development environment for working with Sweave. So far, it
doesn't seem to
2003 Jul 11
1
3d plot with different levels done in different colors
I would like a 3d plot of a matrix such that individual trapezoids
that make up the surface are colored according to the z-value of that
point (or preferably the midpoint of its four corners, or something
similar). MS Excel has something like that.
I know that persp can have an nx by ny matrix its "col" argument, I
just don't know how to generate that matrix. To calculate the