Displaying 20 results from an estimated 3000 matches similar to: "str and class"
2006 Dec 14
3
Model formula question
Hi all,
I'm not familiar with R programming and I'm trying to reproduce a
result from a paper.
Basically, I have a dataset which I would like to model in terms of
successive increments, i.e. (y denote empirical values of y)
y_1 = y1,
y_2 = y1 + delta1,
y_3 = y1 + delta1 + delta2.
...
y_m = y1 + sum_2^m delta j
where delta_j donote successive increments in the y-values, i.e.
delta
2005 Oct 12
1
Using matprod from array.c
Hi,
I was wondering if I could use the matprod function from array.c in my own C routine. I tried the following as a test
/* my_matprod.c */
# include <Rinternals.h> /* for REAL, SEXP etc */
# include <R_ext/Applic.h> /* array.c says need for dgemm */
/* following copied from array.c */
static void matprod(double *x, int nrx, int ncx,
double *y, int nry, int ncy, double *z)
2005 Oct 03
1
storage.mode, C data types and speed
Hi,
I am trying to speed up part of an algorithm in which certain columns of a large matrix (X) are replaced by the element-wise product of a matrix (M) and a vector (v). In R, the code might be
X[, ind] <- M * v
I have written a small C routine to do this for me, but the timing depends on how I define the storage.mode of the objects in R and the data types in C, in a way which I don't
2008 May 14
0
Cook's Distance in GLM (PR#9316)
Well I suppose a warning's not going to hurt. Even in a case like the
occupationalStatus example where you know some points have been fitted
exactly, it might be useful to be reminded that the standardised
residuals for these points are then NaN and cannot be displayed. Of
course when you don't know in advance that this issue will arise, there
is even more reason to give a warning.
2008 May 09
0
Incorrect fix for PR#9316: Cook's Distance & plot.lm
Bug PR#9316 noted an inconsistency between the Cook's distance contours
on plot.lm(x, which = 5) and the values given by cooks.distance(x) -- as
shown in plot.lm(x, which = 4) -- for glms:
http://bugs.r-project.org/cgi-bin/R/Analyses-fixed?id=9316;user=guest;selectid=9316
The suggested fix was to modify the contour levels by a dispersion
factor, implemented as follows:
dispersion <-
2006 Jan 18
2
Loading of namespace on load of .Rdata (was strange behaviour of load)
Last week Giovanni Parrinello posted a message asking why various packages were loaded when he loaded an .Rdata file. Brian Ripley replied saying he thought it was because the saved workspace contained a reference to the namespace of ipred. (Correspondence copied below).
This begs the question: how did the reference to the namespace of ipred come to be in the .Rdata file? Brian did say it is
2008 Nov 12
1
Understanding glm family documentation: dev.resids
Hi all
Consider the family function, as used by glm. The help page says the value of the family object is a list, one element of which is the following:
dev.resids function giving the deviance residuals as a function of (y, mu, wt).
But reading any of the family functions (eg poisson) shows that dev.resids is a function that computes the *square* of the deviance residuals (at least, by
2008 Nov 06
1
nls: Fitting two models at once?
Hello,
I'm still a newbie user and struggling to automate some analyses from
SigmaPlot using R. R is a great help for me so far!
But the following problem makes me go nuts.
I have two spectra, both have to be fitted to reference data. Problem: the
both spectra are connected in some way: the stoichiometry of coefficients
"cytf.v"/"cytb.v" is 1/2.
{{In the SigmaPlot
2015 Apr 29
2
Formula evaluation, environments and attached packages
Hi!
Some time ago, I replaced calls to library() with calls to
requireNamespace() in my package logmult, in order to follow the new
CRAN policies. But I just noticed it broke jackknife/bootstrap using
several workers via package parallel.
The reason is that I'm running model replicates on the workers, and the
formula includes non-standard terms like Mult() which are provided by
gnm. If gnm
2009 Feb 25
2
[R] length 1 offset in glm (& lm)
This post about length 1 offsets on R help seems to have been ignored
(sorry deleted original email - is there a way to continue thread in
this case?)
https://stat.ethz.ch/pipermail/r-help/2009-February/189352.html
It does seem to be a bug, in that glm does not behave as documented. In
fact the same bug applies to lm as well.
I don't think the suggested fix works though - Y isn't
2006 Jan 18
0
Loading of namespace on load of .Rdata (was strange behaviour of load)
Last week Giovanni Parrinello posted a message asking why various packages were loaded when he loaded an .Rdata file. Brian Ripley replied saying he thought it was because the saved workspace contained a reference to the namespace of ipred. (Correspondence copied below).
This begs the question: how did the reference to the namespace of ipred come to be in the .Rdata file? Brian did say it is
2009 Feb 12
3
proposed simulate.glm method
I have found the "simulate" method (incorporated
in some packages) very handy. As far as I can tell the
only class for which simulate is actually implemented
in base R is lm ... this is actually a little dangerous
for a naive user who might be tempted to try
simulate(X) where X is a glm fit instead, because
it defaults to simulate.lm (since glm inherits from
the lm class), and the
2006 Jun 20
2
Documentation issues [Was: Function hints]
I would like to follow up on another one of the documentation issues raised in the discussion on function hints. Duncan mentioned that the R core were working on preprocessing directives for .Rd files, which could possibly include some sort of include directive. I was wondering if a "includeexamples" directive might also be considered.
It often makes sense to use the same example to
2007 Jan 16
1
nonlinear regression: nls, gnls, gnm, other?
Hi all,
I'm trying to fit a nonlinear (logistic-like) regression, and I'd like
to get some recommendations for which package to use.
The expression I want to fit is something like:
y ~ A * exp(X * Beta1) / (1 + exp(-(x + X * Beta2 - xmid)/scal))
Basically, it's a logistic function, but I want to be able to modify
the saturation amplitude by a few parameters (Beta1) and shift the
2006 Jan 10
2
standardized residuals (rstandard & plot.lm) (PR#8468)
This bug is not quite fixed - the example from my original report now =
works using R-2.2.1, but
plot(Uniform, 6)
does not. The bug is due to
if (show[6]) {
ymx <- max(cook, na.rm =3D TRUE) * 1.025
g <- hatval/(1 - hatval) # Potential division by zero here #
plot(g, cook, xlim =3D c(0, max(g)), ylim =3D c(0, ymx),=20
main =3D main, xlab =3D
2005 Jan 24
2
using eval() with pre-built expression inside function
I'm trying to evaluate a pre-built expression using eval(), e.g.
dataset <- data.frame(y = runif(30, 50,100), x = gl(5, 6))
# one like this
mf <- expression(model.frame(y~x))
eval(mf, dataset, parent.frame())
# rather than this
eval(expression(model.frame(y~x)), dataset, parent.frame())
In the example above there is no problem, the problem comes when I try to do a similar thing
2005 Mar 20
1
Re: [R-SIG-Mac] NaN and linear algebra
No, blas/veclib is tested, so aprt this extreme case you should report
some other more commonly used cases in which something fails on OS X.
This will help us to work it out.
As said, I'll try some tests without using veclib and let you know.
I've fowarded this mail to r-devel, which seems to be the right place,
so for future msg on the subject please use r-devel.
stefano
On
2013 Aug 22
1
Confusion about Depends:, Imports:, Enhances:, import(), inportFrom()
In checking my vcdExtra package, the following NOTE newly appeared
(R-Forge, using R version 3.0.1 Patched (2013-08-20 r63635))
Package in Depends field not imported from: ?gnm?
These packages needs to imported from for the case when
this namespace is loaded but not attached.
In the DESCRIPTION file, I have
Depends: R (>= 2.10), vcd, gnm (>= 1.0.3)
In NAMESPACE:
# we are a vcd
2007 Mar 20
2
Any R function for self-controlled case series method /effect absorption?
Hello,
Has anyone written R functions for applying self-controlled case series
methods (http://statistics.open.ac.uk/sccs/).
In fact only thing needed is to modify glm function to allow absorption
of effect. Eg. in Poisson model individual effect is used as factor, but
it is considered as nuisance term where parameter estimates are not needed.
Could anyone point how absorbing individual
2004 Oct 05
2
Package Installation in RGui (PR#7262)
Full_Name: Heather Turner
Version: 2.0.0
OS: Windows NT
Submission from: (NULL) (137.205.8.2)
I tried using the Packages menu to install the gam package and get the following
output:
> local({a <- CRAN.packages()
+ install.packages(select.list(a[,1],,TRUE), .libPaths()[1], available=a,
dependencies=TRUE)})
trying URL `http://cran.r-project.org/bin/windows/contrib/2.0/PACKAGES'
Content