Displaying 20 results from an estimated 40000 matches similar to: "a couple of things about ":""
2018 Sep 11
2
Modification-proposal for %% (modulo) when supplied with double
Hi all,
Could we modify the "%%" (modulo)-operator to include some tolerance for rounding-errors when supplied with doubles?
It's not much work (patch supplied on the bottom), and I don't think it would break anything, only if you were really interested in analysing rounding differences.
Any ideas about implementing this and overwriting base::`%%`, or would we want another
2018 Sep 11
1
Modification-proposal for %% (modulo) when supplied with double
Duncan, I think Emil realizes that the floating point format isn't
able to represent certain numbers, that's why he is suggesting this
change rather than complaining about our arithmetic being broken.
However, I agree with you that we should not adopt his proposal. It
would not make things more "user friendly" for people. Everyone has a
different application and a different use
2004 Feb 10
3
how to get the GUI directory chooser on Windows?
Dear R-help,
Can anyone tell me if it's possible to call up the "directory chooser" (the
one you get when you click on "File" -> "Change Dir...") in Rgui from the R
command line? Seems like file.choose() can't be used to choose a directory.
This is in R-1.8.1 on WinXPPro.
Any help much appreciated!
Andy
2008 May 01
4
efficient code - yet another question
Dear list members;
The code given below corresponds to the PCA-NIPALS (principal
component analysis) algorithm adapted from the nipals function in the
package chemometrics. The reason for using NIPALS instead of SVD is
the ability of this algorithm to handle missing values, but that's a
different story. I've been trying to find a way to improve (if
possible) the efficiency of the code,
1998 Jun 25
1
all.equal
I'm not sure what the process is for this, but can I get the following all.equal
function put in the R base?
Paul Gilbert
____
all.equal <- function(obj1, obj2,...) {UseMethod("all.equal")}
all.equal.default <- function(obj1, obj2, tolerance=.Machine$double.eps)
{if(mode(obj1) != mode(obj2) ) return("modes differ.")
if (length(obj1) !=
2007 Sep 03
2
Row-Echelon Form
I was looking for an R-package that would reduce matrices to
row-echelon form, but Google was not my friend; any leads?
If not, I wonder if the problem could be expressed in terms of
constraint satisfaction...
2005 Dec 14
3
Fitting binomial lmer-model, high deviance and low logLik
Hello
I have a problem when fitting a mixed generalised linear model with the
lmer-function in the Matrix package, version 0.98-7. I have a respons
variable (sfox) that is 1 or 0, whether a roe deer fawn is killed or not
by red fox. This is expected to be related to e.g. the density of red
fox (roefoxratio) or other variables. In addition, we account for family
effects by adding the mother
2004 Apr 02
3
Single Factor Anova
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Hash: SHA1
Hello all -
As I progress in R I am trying to automate functions I would have
normally farmed out to Excel, SPSS or Statistica. Single factor anova
is one of them. For example, a dataset from NIST StRD
(http://www.itl.nist.gov/div898/strd/anova/AtmWtAg.html) has two groups:
1 2
107.8681568 107.8681079
107.8681465 107.8681344
2004 Jan 09
2
debugging strange segfault
Dear R-devel,
Can anyone give me some hints on how to go about debugging a strange
segfault in my randomForest package? Here's the scoop:
A user reported segfault when running predict() in the randomForest package.
I asked for the data and code. The combination runs fine under WinXPPro,
but does give segfault on one of our Linux boxes running R (1.7.0 through
R-devel_2004-01-08) on
2004 Oct 26
2
need help debugging on Windows
Dear R-devel,
Apologies for bothering y'all with this seemingly perennial question. A
user reported problem with my most recent version of randomForest (4.4-1),
and I was able to reproduce it with his data with R-2.0.0 patched
(2004-10-24) on WinXP Pro. The problem is that it crashes R on Windows.
However, it does not happen on Linux (tried SUSE ES8 on our Opterons and
Quantian on my
2018 Sep 03
2
compairing doubles
Maybe a new Operator could be defined for a fast and easy double
Comparison: `~~`
`~~` <- function (e1, e2) all.equal(e1, e2)
And document it properly.
2006 Mar 16
1
lme4/Matrix: Call to .Call("mer_update_y"...) and LMEoptimize gives unexpected side effect...
Dear all
I want to compute Monte Carlo p-values in lmer-models based on sampled data sets. To speed up calculations, I've tried to use internal functions from the Matrix package (as suggested ealier on the list by Doug Bates).
So I did:
fm2 <- lmer(resistance ~ ET + position + (1|Grp), Semiconductor,method='ML')
simdata<-simulate(fm2,nsim=1)
ynew <- simdata[,1]
mer
2004 Dec 14
3
make check-all failed on SLES8 for x86_64
Hi all,
I've only now noticed that on our Opteron boxes running Suse Enterprise
Server 8 that R-2.0.1 did not pass make chek-all. It bombed in
tests/lapack.R at:
> eigenok <- function(A, E, Eps = 1000 * .Machine$double.eps) {
V <- E$vect
lam <- E$values
stopifnot(abs(A %*% V - V %*% diag(lam)) < Eps, .... [TRUNCATED]
> Ceigenok <- function(A, E, Eps =
2007 Jul 13
2
nearest correlation to polychoric
Dear all,
Has someone implemented in R (or any other language)
Knol DL, ten Berge JMF. Least-squares approximation of an improper correlation matrix by a proper one. Psychometrika, 1989, 54, 53-61.
or any other similar algorithm?
Best regards
Jens Oehlschl?gel
Background:
I want to factanal() matrices of polychoric correlations which have negative eigenvalue. I coded
Highham 2002
2005 Jun 12
2
delete "-character from strings in matrix
Hi!
I have strings where occasionally some "-chars occur.
How can I delete these chars?
I tried it with gsub but using "" as replace does not
work.
Thanks a lot for any hint!
Regards,
Werner
2004 Mar 17
5
build on Irix failed reg-tests
Dear R-devel,
Has anyone seen this problem? We tried building R-1.8.1 (and R-1.9.0 alpha
2004-03-17) on an Irix 6.5 box using
./configure CC="cc -64" F77="f77 -64" --with-tcltk=no --enable-R-shlib
make check failed because NA + 0 gave NaN instead of NA. I've tried both
32- and 64-bit build, with and without --enable-R-shlib. The same symptom
occur in all cases.
Any
2005 Mar 18
3
Non linear modeling
AFAIK most model fitting techniques will only deal with additive errors, not
multiplicative ones. You might want to try fitting:
log(y-x) = a*x + e
which is linear.
Andy
> From: Angelo Secchi
>
> Hi,
> is there a way in R to fit a non linear model like
>
> y=x+exp(a*x)*eps
>
> where a is the parameter and eps is the error term?
> Thanks
> Angelo
>
>
2003 Sep 29
1
can I have a matrix of factors, please?
Dear R-help,
Is it a violation of the S language to have a matrix of factors? What I
would like to have is just a factor object that has dim attribute, and can
be printed (and subsetted) like a matrix; i.e., all columns/rows have the
identical levels. However, I can't get it to work:
> x <- factor(sample(2, 10, replace=TRUE))
> dim(x)<- c(5,2)
> x
[1] 1 2 2 1 2 1 1 1 2 1
2003 Nov 25
2
Lambert's W function
Hello List
does anyone have an R function for the Lambert W function? I need
complex arguments.
[the Lamert W function W(z) satisfies
W(z)*exp(W(z)) = z
but I could'nt even figure out how to use uniroot() for complex z]
--
Robin Hankin
Uncertainty Analyst
Southampton Oceanography Centre
SO14 3ZH
tel +44(0)23-8059-7743
initialDOTsurname at soc.soton.ac.uk (edit in obvious way; spam
2018 Aug 31
2
compairing doubles
El vie., 31 ago. 2018 a las 16:00, Mark van der Loo
(<mark.vanderloo at gmail.com>) escribi?:
>
> how about
>
> is_evenly_spaced <- function(x,...) all.equal(diff(sort(x)),...)
This doesn't work, because
1. all.equal does *not* return FALSE. Use of isTRUE or identical(.,
TRUE) is required if you want a boolean.
2. all.equal compares two objects, not elements in a vector.