Displaying 20 results from an estimated 1000 matches similar to: "glm or transformation of the response?"
2005 Dec 01
2
Minimizing a Function with three Parameters
Hi,
I'm trying to get maximum likelihood estimates of \alpha, \beta_0 and
\beta_1, this can be achieved by solving the following three equations:
n / \alpha + \sum\limits_{i=1}^{n} ln(\psihat(i)) -
\sum\limits_{i=1}^{n} ( ln(x_i + \psihat(i)) ) = 0
\alpha \sum\limits_{i=1}^{n} 1/(psihat(i)) - (\alpha+1)
\sum\limits_{i=1}^{n} ( 1 / (x_i + \psihat(i)) ) = 0
\alpha \sum\limits_{i=1}^{n} (
2015 Jun 10
2
Duda glmer
Hola,
Tengo una base de datos con estructura jerárquica en la que quiero
clasificar observaciones en distintas categorías.
En el caso más simple, tengo una variable con dos categorías (variable
Y1) y dentro de cada una de ellas hay otras dos categorías (variable
Y2). Además tengo una variable explicativa cuantitativa discreta X.
El banco de datos sería de este tipo:
X Y1 Y2
5 0 1
9 0 0
2
2002 Dec 04
1
use of offset - clarification
Hi Listers,
seems I have forgotten some basics re offset in glm:
data:
counts (y) from locations off different size (area),
explanatory variable: x
Model:
y ~ x+offset(area)
Predictions (pred) using Poisson errors
plot(x,y) and points(x,pred) gives neat "line" of estimated values.
However, for ease of understanding graphs are better using plot(x,y/area).
Question:
How to display
2005 Nov 24
1
residuals in logistic regression model
In the logistic regression model, there is no residual
log (pi/(1-pi)) = beta_0 + beta_1*X_1 + .....
But glm model will return
residuals
What is that?
How to understand this? Can we put some residual in the logistic regression
model by replacing pi with pi' (the estimated pi)?
log (pi'/(1-pi')) = beta_0 + beta_1*X_1 + .....+ ei
Thanks!
[[alternative HTML version deleted]]
2010 Jan 25
3
binary
Hi all
Assume I have a data set xx;
Group: 1=group1 ?, 2=group2
IQ: ?1= High, 0 =low
fit <- glm(IQ ~group, data = xx, family = binomial())
summary(fit)
Results
?????? ????????????Estimate Std. Error z value Pr(>|z|)
(Intercept) -2.55456??? 0.210 -12.273? < 5e-16 ***
group????????? 0.36180 ?????0.076?? 3.952 ????5.24e-05 ***
the odd ratio = exp(0.36180 )= 1.435912
My question
2007 Sep 13
1
Problem using xtable on an array
Hi all
I know about producing a minimal example to show my problem. But I'm
having trouble producing a minimal example that displays this
behaviour, so please bear with me to begin with.
Observe: I create an array called model.mat. Some details on this:
> str(model.mat)
num [1:18, 1:4] -0.170 -0.304 -2.617 2.025 -1.610 ...
- attr(*, "dimnames")=List of 2
..$ : chr
2008 Jun 15
2
R vs SAS and HLM on multilevel analysis- basic question
Hi R users!
I am trying to learn some multilevel analysis, but unfortunately i am now very confused. The reason: http://www.ats.ucla.edu/stat/hlm/seminars/hlm_mlm/mlm_hlm_seminar.htm
http://www.ats.ucla.edu/stat/sas/seminars/sas_mlm/mlm_sas_seminar.htm
and
MlmSoftRev. pdf from mlmRev package.
>From what i see, the first two links seem to declare the level one variable as a random part (i
2011 Sep 07
1
linear regression, log-transformation and plotting
Hello,
I've some questions concerning log-transformations and plotting of the regression lines. So far as I know is it a problem to log-transform values smaller than 1 (0-1). In my statistics lecture I was told to do a log(x+1) transformation in such cases. So I provide here a small example to explain my questions:
# Some example data for testing
a1
2017 Oct 23
3
Linear regression with tranformed dependant variable
Dear all,?I am trying to fit a multiple linear regression model with a transformed dependant variable (the normality assumption was not verified...).?I have realised a sqrt(variable) transformation...?The results are great, but I don't know how to interprete the beta coefficients... Is it possible to do another transformation to get interpretable beta coefficients to express the variations in
2009 Dec 04
2
curve fitting to data
Hi to all
This is the first time I am quoting a question and I hope, my
question is not too basic...
For the following data, I wish to draw a fitted curve.
x <- c(123,129,141,144,144,145,149,150,158,159,163,174,183,187,242,248)
y <-
c(14.42,26.96,31.3,19.95,36.36,15.4,24.76,35.39,28.07,40.97,26.23,42.83,46.53,14.79,49.18,48.08)
If I plot the data, it looks somehow that a logistic
2009 Jun 09
2
Isolating a single plot from plots produced simultaneously
Dear R-Help,
I am using the 'mfp' package. It produces three plots (as I am using
the Cox model) simultaneously which can be viewed together using the
following code:
fit <- mfp(Surv(rem.Remtime,rem.Rcens)~fp(age)+strata(rpa),family=cox,data=nearma,select=0.05,verbose=TRUE)
par(mfrow=c(2,2))
plot(fit)
They can be viewed separately but the return key must be pressed after
each graph
2017 Oct 23
0
Linear regression with tranformed dependant variable
Hello,
R-Help answers questions on R code, your question is about statistics.
You should try posting the question to
https://stats.stackexchange.com/
Hope this helps,
Rui Barradas
Em 23-10-2017 18:54, kende jan via R-help escreveu:
> Dear all, I am trying to fit a multiple linear regression model with a transformed dependant variable (the normality assumption was not verified...). I have
2012 May 15
1
Lattice: Add abline to Single Value qqmath() Plot
The data are not normally distributed when untransformed and I'm trying
various transformations to see if any would be appropriate to use. The
lattice book (fig. 3.10) shows a 2-sample Q-Q plot with an abline but the
code for the figure does not include the line.
I'd appreciate a pointer to a reference on how to add an abline to a
one-sample qqmath() plot in lattice.
Rich
2004 Aug 06
2
Status.xml
On Wednesday 17 December 2003 15:53, Macsym wrote:
> Hi everybody,
>
> If I understand well, the purpose of XSL files is re-formatting XML files.
> When I checked the admin folder, I saw status.xsl but I did not see the
> source XML file (status.xml?).
>
> If status.XML (NOT status.XSL) exists, where is it located? Is there any
> way I can store status.xml or status.xsl on
2010 Feb 12
1
using mle2 for multinomial model optimization
Hi there
I'm trying to find the mle fo a multinomial model ->*L(N,h,S?x)*. There
is only *N* I want to estimate, which is used in the number of successes
for the last cell probability. These successes are given by:
p^(N-x1-x2-...xi)
All the other parameters (i.e. h and S) I know from somewhere else.
Here is what I've tried to do so far for a imaginary data set:
2004 Oct 08
1
nlme vs gls
Dear List:
My question is more statistical than R oriented (although it originates
from my work with nlme). I know statistical questions are occasionally
posted, so I hope my question is relevant to the list as I cannot turn
up a solution anywhere else. I will frame it in the context of an R
related issue.
To illustrate the problem, consider student achievement test score data
with multiple
2004 Nov 11
5
expressions and paste
I have written a function to plot data which will be used for various different chemistries.
A simplified version is:
plot_data <- function(risk,levels,chem,sd2,measure){
plot(risk, levels,main=paste ("per", sd2, measure, "\n in usual", chem))
}
The problem is with the title.
This works fine if the variable "chem" is just text, but if it is an expression then
2000 Jun 16
3
login reporting (utmp?) problem on Linux
I have recently compiled and installed openssh-2.1.1p1 on a linux box.
The login reporting does not seem to work properly.
When logging into the box via ssh (protocol 1) utmp shows the user logged
in and the tty properly, but the field for the login date/time and the
field for originating host contain all NULLs.
Is anyone else seeing this same behavior, or have I just done something
really
2018 Aug 07
2
id <username> - doesnt list all groups
Hello,
my enviroment:
All Servers are Ubuntun 16.04-18.04
SAMBA AD DC Server and several SAMABA DOMAIN MEMBER (connected via
WINBIND). In ADDC I've created a group "restrictaccess" and added some
users.
Now when im typing "id <username>" on a Domain Member, for some users
the group "restrictaccess" are listed for some not!
For example:
ON DC:
#
2009 Aug 26
3
tweedie and lmer
Hello all,
I have count data with about 36% of observations being zeros. I found
in some of the examples of the r-help mail archives that a tweedie
family of distributions could be used to fit a model with random
effects. Upon installing the tweedie package and attempting to fit the
following model:
lmer(SUS ~ 1 + (1|