Displaying 20 results from an estimated 100 matches similar to: "calculate likelihood based on logit regression"
2005 Aug 05
1
question regarding logit regression using glm
I got the following warning messages when I did a
binomial logit regression using glm():
Warning messages:
1: Algorithm did not converge in: glm.fit(x = X, y =
Y, weights = weights, start = start, etastart =
etastart,
2: fitted probabilities numerically 0 or 1 occurred
in: glm.fit(x = X, y = Y, weights = weights, start =
start, etastart = etastart,
Can some one share your thoughts on how to
2006 Oct 13
4
nontabular logistic regression
Hi. I'm attempting to fit a logistic/binomial model so I can determine
the influence of landscape on the probability that a box gets used by a
bird. I've looked at a few sources (MASS text, Dalgaard, Fox and
google) and the examples are almost always based on tabular predictor
variables. My data, however are not. I'm not sure if that is the
source of the problems or not because the
2006 Apr 23
1
Question about bicreg
Dear Adrian and Ian (and r-helpers),
I encountered a curious result in developing an example using the bicreg
function in the BMA package: I noticed that pairs of models with equal R^2
and equal numbers of predictors had nevertheless different BIC values.
Looking at the bicreg function, the definition of BIC appears to be the
usual one, or close to it [bic <- n * log(1 - r2/100) + (size - 1) *
2007 Dec 09
2
Large determinant problem
I thought I would have another try at explaining my problem. I think that
last time I may have buried it in irrelevant detail.
This output should explain my dilemma:
> dim(S)
[1] 1455 269
> summary(as.vector(S))
Min. 1st Qu. Median Mean 3rd Qu. Max.
-1.160e+04 0.000e+00 0.000e+00 -4.132e-08 0.000e+00 8.636e+03
> sum(as.vector(S)==0)/(1455*269)
[1]
2000 May 09
4
Dispersion in summary.glm() with binomial & poisson link
Following p.206 of "Statistical Models in S", I wish to change
the code for summary.glm() so that it estimates the dispersion
for binomial & poisson models when the parameter dispersion is
set to zero. The following changes [insertion of ||dispersion==0
at one point; and !is.null(dispersion) at another] will do the trick:
"summary.glm" <-
function(object, dispersion =
2009 Jan 12
1
help on nested mixed effects ANOVA
Hello,
I am trying to run a mixed effects nested ANOVA but none of my codes
are giving me any meaningful results and I am not sure what I am doing
wrong. I am a new user on R and would appreciate some help.
The experimental design is that I have some frogs that have been
exposed to three acoustic Treatments and I am measuring neural
activity (egr), in 12 brain regions. Some frogs also called
2008 Jun 17
2
Accessing Max/Min Value of Density Function
Dear all,
Currently I have the following output
> mydensity <- density(x)
> print(mydensity)
x y
Min. : -92.14 Min. :0.000e+00
1st Qu.: 356.66 1st Qu.:5.530e-09
Median : 805.45 Median :4.681e-05
Mean : 805.45 Mean :5.564e-04
3rd Qu.:1254.24 3rd Qu.:3.370e-04
Max. :1703.04 Max. :5.541e-03
How can I access the Max value of
2009 Nov 12
1
naive "collinear" weighted linear regression
Hi there
Sorry for what may be a naive or dumb question.
I have the following data:
> x <- c(1,2,3,4) # predictor vector
> y <- c(2,4,6,8) # response vector. Notice that it is an exact,
perfect straight line through the origin and slope equal to 2
> error <- c(0.3,0.3,0.3,0.3) # I have (equal) ``errors'', for
instance, in the measured responses
Of course the
2008 Mar 02
0
coxpath() in package glmpath
Hi,
I am new to model selection by coefficient shrinkage
method such as lasso. And I became particularly
interested in variable selection in Cox regression by
lasso. I became aware of the coxpath() in R package
glmpath does lasso on Cox model. I have tried the
sample script on the help page of coxpath(), but I
have difficult time understanding the output.
Therefore, I would greatly appreciate if
2009 Feb 20
0
residuals from a fractional arima model and other questions
Dear list and Martin,
I'm testing different approaches to fit an electricity demand time series and come upon the fracdiff package (v 1.3-1) for fitting fractional ARIMA models. The following questions are motivated by this package.
1. Despite having a help page, the residuals and fitted functions don't seem to have implementation, or did i miss something obvious? Alternatively, having a
2010 Aug 25
3
approxfun-problems (yleft and yright ignored)
Dear all,
I have run into a problem when running some code implemented in the
Bioconductor panp-package (applied to my own expression data), whereby gene
expression values of known true negative probesets (x) are interpolated onto
present/absent p-values (y) between 0 and 1 using the *approxfun -
function*{stats}; when I have used R version 2.8, everything had
worked fine,
however, after updating
2011 Jul 25
1
error in survival analysis
This is a simple R program that I have been trying to run. I keep running into the "singular matrix" error. I end up with no sensible results. Can anyone suggest any changes or a way around this?
I am a total rookie when working with R.
Thanks,
Rasika
> library(survival)
Loading required package: splines
> args(coxph)
function (formula, data, weights, subset, na.action, init,
2011 Mar 02
2
problem with glm(family=binomial) when some levels have only 0 proportion values
Hello everybody
I want to compare the proportions of germinated seeds (seed batches of
size 10) of three plant types (1,2,3) with a glm with binomial data
(following the method in Crawley: Statistics,an introduction using R,
p.247).
The problem seems to be that in two plant types (2,3) all plants have
proportions = 0.
I give you my data and the model I'm running:
success failure
2007 Jul 21
0
Binomial multi-level (hierarchical) modelling [partly stats question, not completely R related]
Dear all,
This question is partly statistics and partly R and I apologise in
advance for my (usual) verbosity! My data is a little more complicated
that this suggests, but essentially I have proportion data from
different studies (id), each from a specific country and region of the
World. I would like to examine the variables that affect the
proportion, but these factors are hierarchical. In case
2011 Mar 08
3
This is supposed to predict a time series?!
Hello,
I just ran the predict.StructTS function using the AirPassengers data
and got a ridiculous result. Here's what I ended up with:
http://24.210.155.111/PredictWhat!.pdf
Who wrote this? Am I seriously supposed to think this function would
accurately predict a time series?
-AnalogKid
2012 Dec 15
3
interfacing with .Call
Hi
My code is as following:
#include <R.h>
#include <Rinternals.h>
//* the Projector part *//
void Projector(double *L, int *dimL, double *G, int *dimG, double *W, int
*dimW, int *xymod, int *dimxy, double *modif, int *dimif, double *Lsum)
{ ...}
//* the interface part *//
#define getDim(A) INTEGER(coerceVector(getAttrib(A,R_DimSymbol), INTSXP))
SEXP Projector5(SEXP L, SEXP G,
2003 Jan 23
0
Re: R-help digest, Vol 1 #51 - 13 msgs
> Subject: [R] Question on running tseries::garch on Mac OSX
> Date: Sat, 18 Jan 2003 15:58:50 -0800
> From: Nicholas Waltner <nwaltner at attbi.com>
> To: <R-help at stat.math.ethz.ch>
>
> Hello,
>
> When I run the garch examples, I get the following output:
>
> > dax.garch <- garch(dax)
>
> ***** ESTIMATION WITH ANALYTICAL GRADIENT *****
2011 Oct 10
1
Linear programming problem, RGPLK - "no feasible solution".
In my post at https://stat.ethz.ch/pipermail/r-help/2011-October/292019.html I included an undefined term "ej". The problem code should be as follows. It seems like a simple linear programming problem, but for some reason my code is not finding the solution.
obj <- c(rep(0,3),1)
col1 <-c(1,0,0,1,0,0,1,-2.330078923,0)
col2 <-c(0,1,0,0,1,0,1,-2.057855981,0)
col3
2004 Jul 05
2
Failing on reading a "slightly big" dataset
I have a file with 4 columns per line, all pipe delimited.
$ wc -l cmie_firm_data.text
89325 cmie_firm_data.text
$ ls -al cmie_firm_data.text
-rw-r--r-- 1 ajayshah ajayshah 4415637 Jul 5 15:25 cmie_firm_data.text
$ awk -F\| '(NF != 4)' cmie_firm_data.text
$ head cmie_firm_data.text
All figures are for the year 20030331|||
Company|GVA Less Interest (Rs. thousand)|Interest (Rs.
2010 Nov 10
2
prcomp function
Hello,
I have a short question about the prcomp function. First I cite the
associated help page (help(prcomp)):
"Value:
...
SDEV the standard deviations of the principal components (i.e., the square
roots of the eigenvalues of the covariance/correlation matrix, though the
calculation is actually done with the singular values of the data matrix).
ROTATION the matrix of variable loadings