Displaying 20 results from an estimated 2000 matches similar to: "How to produce glm graph"
2010 Nov 20
1
How to produce a graph of glms in R?
I'm very new to R and modeling but need some help with visualization of glms.
I'd like to make a graph of my glms to visualize the different effects of
different parameters.
I've got a binary response variable (bird sightings) and use binomial glms.
The 'main' response variable is a measure of distance to a track and the
parameters I'm testing for are vegetation
2011 Jan 12
1
how to change strip text of effect plot
Dear r heper,
How can I change the strip text, for example (16,23] in the following
example, to other more informative text such as "high level" on the
fly?
library(effects)
Cowles$ex2 <- cut(Cowles$extraversion,3)
mod.cowles <- glm(volunteer ~ sex+neuroticism*ex2,data=Cowles, family=binomial)
eff.cowles <- allEffects(mod.cowles)
plot(eff.cowles,
2010 May 04
1
help overlay scatterplot to effects plot
I have a process where I am creating a effects plot similar to the cowles effect example. I would like to add the point estimates to the effects plot, can someone show me the correct syntax. I have included the "R" effects example, so you can show me the correct syntax. Thanks
mod.cowles <- glm(volunteer ~ sex + neuroticism*extraversion,
data=Cowles, family=binomial)
2009 Apr 28
2
effects package --- add abline to plot
Hello, I am not having success in a simple task. Using the effects package, I would like to add reference lines at probability values of 0.1 – 0.6 on a plot of the effects. The plot command works, but following up with an abline command produces the message “plot .new has not been called yet”, and of course the reference lines were not added.
Looking through past R help lists, there was a
2006 Sep 13
3
unexpected result in glm (family=poisson) for data with an only zero response in one factor
Dear members,
here is my trouble: My data consists of counts of trapped insects in different attractive traps. I usually use GLMs with a poisson error distribution to find out the differences between my traitments (and to look at other factor effects). But for some dataset where one traitment contains only zeros, GLM with poisson family fail to find any difference between this particular traitment
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
2011 Mar 31
1
rank of Matrix
Dear list,
Can anyone tell me how to obtain the rank of a sparse Matrix, for
example from package Matrix (class dgCMatrix)? Here is an example of
QR decomposition of a sparse matrix (from the sparseQR class help).
library(Matrix)
data(KNex)
mm <- KNex$mm
str(mmQR <- qr(mm))
Similarly, using the functions/classes from the relatively new
MatrixModels package:
library(MatrixModels)
2006 Apr 23
1
Comparing GLMMs and GLMs with quasi-binomial errors?
Dear All,
I am analysing a dataset on levels of herbivory in seedlings in an
experimental setup in a rainforest.
I have seven classes/categories of seedling damage/herbivory that I want to
analyse, modelling each separately.
There are twenty maternal trees, with eight groups of seedlings around each.
Each tree has a TreeID, which I use as the random effect (blocking factor).
There are two
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
2000 Apr 19
1
scale factors/overdispersion in GLM: possible bug?
I've been poking around with GLMs (on which I am *not* an expert) on
behalf of a student, particularly binomial (standard logit link) nested
models with overdispersion.
I have one possible bug to report (but I'm not confident enough to be
*sure* it's a bug); one comment on the general inconsistency that seems to
afflict the various functions for dealing with overdispersion in GLMs
2006 Oct 12
2
how to get the variance-covariance matrix/information of alpha and beta after fitting a GLMs?
Dear friends,
After fitting a generalized linear models ,i hope to get the variance of
alpha,variance of beta and their covariance, that is , the
variance-covariance matrix/information of alpha and beta , suppose *B* is
the object of GLMs, i use attributes(B) to look for the options ,but can't
find it, anybody knows how to get it?
> attributes(B)
$names
[1] "coefficients"
2011 Jul 22
1
cv.glm and "longer object length is not a multiple of shorter object length" error
Hi,
I've done some searching where others have had trouble with this error (or
"warning" actually), but I'm unable to solve my problem. I have a data
sheet with 13 columns and 36 rows. Each column has exactly the same number
of rows. I've created glms and now want to do cross-validation on 2 of
them. Please be gentle-- I'm new to R (and statistics, too, for that
2004 Jan 14
2
Binomial glms with very small numbers
V&R describes binomial GLMs with mortality out of 20 budworms.
Is it appropriate to use the same approach with mortality out of
numbers as low as 3? I feel reticent to do so with data that is not
very continuous. There are one continuous and one categorical
independent variables.
Would it be more appropriate to treat the response as an ordered
factor with four levels? If so, what family
2005 Mar 03
1
Negative binomial regression for count data
Dear list,
I would like to fit a negative binomial regression model as described in "Byers AL, Allore H, Gill TM, Peduzzi PN., Application of negative binomial modeling for discrete outcomes: a case study in aging research. J Clin Epidemiol. 2003 Jun;56(6):559-64" to my data in which the response is count data. There are also 10 predictors that are count data, and I have also 3
2000 Aug 14
2
conf. int. for lm() and Up-arrow
Dear all,
Is there any function for calculating confidence limits
for coefficients in an lm() object? I know of the
confint() function in the MASS library working very
well on my binomial GLMs and I have tried it (using glm
() , family=gaussian) but it gives NAs according to
below. Does the confint() function not accept gaussian
GLMs? Could there be convergence problems in the GLM?
Note the
2007 Nov 28
3
Recommended textbooks for R?
Hi everyone!
I've recently begun to learn R for my job as the IT department suffers
from lack of funding for new software. I was talking to the guy in
charge of Requisitions and have found out the budget for books is in
great shape.
So, I'm curious what books people know of that have R examples and are
good for:
1.) Uni and Multivariate Time Series Analysis/Forecasting
2.) GLMs (at
2004 Jun 14
2
Member Server in Active Directory
I'm trying to join a Samba 3.0.4 (compiled from source on Debian) to an
Active Directory as a member server. I believe Kerberos is configured
correctly as kinit creates a ticket for the realm. Executables appear to have
support for Kerberos and LDAP (smbd -b | grep KRB and grep LDAP) return OK.
When I try to join the AD with
net ads join -U myadminusername
I'm prompted for my
2010 Jun 21
1
glm, poisson and negative binomial distribution and confidence interval
Dear list,
I am using glm's to predict count data for a fish species inside and outside
a marine reserve for three different methods of monitoring.
I run glms and figured out the best model using step function for each
methods used.
I predicted two values for my fish counts inside and outside the reserve
using means of each of the covariates (using predict() )
therefore I have only one value
2008 Jul 07
2
Running "all possible subsets" of a GLM (binomial) model
I have spent a fair amount of time looking for a package that is automated
to run glm (binomial) regression models with all possible subsets of my
independent variables. Something akin to Lumley's "leaps" package, but can
be applied to glms, not just lms; or something similar to Stata's brute
force "tryem" function? If anyone can point me in the right direction I
2012 Feb 09
2
GLM - guess the distribution of the response variable
Dear all,
I have question regarding GLMs:
I have a discrete response variable and a continuous explaining
variable. Like this:
http://www.myimg.de/?img=example1db0f.jpg
I want to use a GLM to investigate. I have to specify the "familiy of
the distribution of the response variable" - or, maybe more precise, the
"family of the distribution of the residuals of the response