Displaying 20 results from an estimated 300 matches similar to: "MASS::loglm - exploring a collection of models with add1, drop1"
2010 Nov 08
1
unknown dimensions for loglm
Dear R-help community,
I am working with multidimensional contingency tables and I am having
trouble getting loglm to run on all dimensions without typing out each
dimension.
I have generated random data and provided output for the results I want
below:
d1.c1 <- rnorm(20, .10, .02)
d1.c2 <- rnorm(20, .10, .02)
d2.c1 <- rnorm(20, .09, .02)
d2.c2 <- rnorm(20, .09, .02)
d3.c1 <-
2013 Jul 06
0
fitting the null loglinear model with MASS::loglm??
The null loglinear model is an intercept-only model for log frequency,
log(f) = \mu
For a one-way table the test of the null model is the same as the
chisq.test.
This can be fit using loglin(), but I don't think there is any way to
specify this using MASS::loglm
> t1<- margin.table(Titanic,1)
> t1
Class
1st 2nd 3rd Crew
325 285 706 885
> loglin(t1, NULL)
0
2003 Oct 30
0
loglm() uses only a reference to data, and not data itsel f - is that on purpose??
loglm() is a port of an original written for S-PLUS. The fact that it
carries only a reference to the data frame is neither intentional nor
unintentional, but an unnoticed side-effect. I can see advantages both
ways. (I'm not so sure, either, that what you say is standard behaviour for
model fitting functions really is so universal.)
It would not be too hard to come up with a version that
1999 Feb 18
1
[R] possible bug in loglm (PR#122)
Bug report: there is a problem with loglm (or some underlying code)
when used with updating within a function. For example, this code
works as expected, when used outside a function:
-------------------------------------------------
library(MASS)
2007 May 23
0
Replicated LR goodness-of-fit tests, heterogeneity G, with loglm?
I have numerous replicated goodness-of-fit experiments (observed compared to expected counts in categories) and these
replicates are nested within a factor.
The expected counts in each cell are external (from a
scientific model being tested). The
calculations I need within each level of the nesting factor are a heterogeneity
G test, with the total G and the pooled G across replicates. Then I
1999 Apr 14
2
No LOGLM coefficients
Dear R-helpers,
Im trying to fit a Log-linear model on a dataset with bird counts from
60 sites over 14 years for 12 months each (factors for the models). One
of the aims is to predict the missing values in this dataset with model
predictions.
Ive first tried to work with GLM's, that worked fine except for models
with one or more interaction-terms. The GLMs run, run .. for hours. So I
2009 Jan 14
1
loglm fitting
Dear all,
sorry to bother you all with this but I've been trying to use the loglm in
MASS package (v2.8.0) and cannot get any sensible output.
I'm wondering am I doing something very foolish or missing something
obvious.
For example, I tried the documentation help(loglm) example - here's the
code
# Case 1: frequencies specified as an array.
sapply(minn38,
2007 Mar 13
3
inconsistent behaviour of add1 and drop1 with a weighted linear model
Dear R Help,
I have noticed some inconsistent behaviour of add1 and drop1 with a
weighted linear model, which affects the interpretation of the results.
I have these data to fit with a linear model, I want to weight them by
the relative size of the geographical areas they represent.
_________________________________________________________________________________________
> example
2010 Oct 25
2
extracting characteristics of datasets from data()
I can use data() to find the available datasets in a package, but I'd
like to extract and display some additional
information for each dataset than what is provided by data(), e.g.,
class() and dim() for datasets for which
these are available. I'm stuck on using using lapply properly with
objects, rather than the names of objects
that I get from data()
Example:
> DS <-
2011 Mar 11
1
Unintuitive backwards-incompatible behaviour with rsync -a --link-dest --size-only
I use rsync to backup my system, using a command-line such as the following:
> rsync [src] [dst] -a --link-dest --size-only
In this case, [src] is produced by a command that makes no attempt to
preserve timestamps ("svnadmin hotcopy", in this case). That's why I use
--size-only.
Here's the rub: identical files aren't hard-linked like I expect them to be.
They're full
2007 Sep 03
1
Ask alpha cronbach and Hoyt method
Dear all, i need help about comparing 2 alpha cronbach. How to derive W statistic. Are alpha cronbach and Hoyt's method using ANOVA identical? Thank you for your help.
Regards
---------------------------------
Luggage? GPS? Comic books?
[[alternative HTML version deleted]]
2013 Sep 12
6
declaring package dependencies
I received the following email note re: the vcdExtra package
> A vcd update has shown that packages TIMP and vcdExtra are not
> declaring their dependence on colorspace/MASS: see
>
> http://cran.r-project.org/web/checks/check_results_vcdExtra.html
But, I can't see what to do to avoid this, nor understand what has
changed in R devel.
Sure enough, CRAN now reports errors in
2004 Jul 31
3
Openldap samba 3.0.5 net group add does not work
When I run net add groupmap rid=512 ntgroup="Domain Admins"
UNIXgroup="ntadmins" i get this error:
adding entry for group Domain Admins failed!
The error isn't very specific and the log doesn't show any error. I look in
the log (log level -1 in slapd.conf) and I can tell it is able to search. I
can post the syslog if you need it. I think their is an error in my
2005 Aug 04
0
add1.lm and add1.glm not handling weights and offsets properly (PR#8049)
I am using R 2.1.1 under Mac OS 10.3.9.
Two related problems (see notes 1. and 2. below) are illustrated by
results of the following:
y <- rnorm(10)
x <- z <- 1:10
is.na(x[9]) <- TRUE
lm0 <- lm(y ~ 1)
lm1 <- lm(y ~ 1, weights = rep(1, 10))
add1(lm0, scope = ~ x) ## works ok
add1(lm1, scope = ~ x) ## error
lm2 <- lm(y ~ 1, offset = 1:10)
add1(lm0, scope = ~ z) ##
2005 Aug 05
0
(PR#8049) add1.lm and add1.glm not handling weights and
David,
Thanks.
The reason add1.lm (and drop1.lm) do not support offsets is that lm did
not when they were written, and the person who added offsets to lm did not
change them. (I do wish they had not added an offset arg and just used the
formula as in S's glm.) That is easy to add.
For the other point, some care is needed if 'x' is supplied and the upper
scope reduces the number
2013 Jun 25
1
F statistic in add1.lm vs add1.glm
Should the F statistic be the same when using add1() on models created by lm and glm(family=gaussian)?
They are in the single-degree-of-freedom case but not in the multiple-degree-of-freedom case.
MASS:addterm shows the same discrepancy. It looks like the deviance (==residual sum of squares) gets
divided by the number of degrees of freedom for the term twice in add1.glm. Using anova() on the
2006 Apr 01
1
Nested error structure in nonlinear model
I am trying to fit a nonlinear regression model to data. There are
several predictor variables and 8 parameters. I will write the model as
Y ~ Yhat(theta1,...,theta8)
OK, I can do this using nls() - but "only just" as there are not as many
observations as might be desired.
Now the problem is that we have a factor "Site" and I want to include a
corresponding error
2010 Jul 06
0
Add1 w/ coef estimates?
I was wondering if there is anyway to have Add1() display the coefficient
estimates for each candidate predictor along with the F test. This is for
lm() btw.
Thanks
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2006 Mar 31
1
add1() and glm
Hello,
I have a question about the add1() function and quasilikelihoods for GLMs.
I am fitting quasi-Poisson models using glm(, family = quasipoisson).
Technically, with the quasilikelihood approach the deviance does not have
the interpretation as a likelihood-based measure of sample information.
Functions such as stepAIC() cannot be used. The function add1() returns
the change in the scaled
2007 May 21
2
Source code of add1
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