similar to: multinomial estimation output stat question - not R question

Displaying 20 results from an estimated 20000 matches similar to: "multinomial estimation output stat question - not R question"

2007 Mar 26
1
fitted probabilities in multinomial logistic regression are identical for each level
I was hoping for some advice regarding possible explanations for the fitted probability values I obtained for a multinomial logistic regression. The analysis aims to predict whether Capgras delusions (present/absent) are associated with group (ABH, SV, homicide; values = 1,2,3,), controlling for previous violence. What has me puzzled is that for each combination the fitted probabilities are
2007 Apr 05
1
p value for coefficients in multinomial model
Dear all, 1)how can I easily get p value for the coefficients of factors in a multinomial model? 2)why the p values for "type III" test with Anova are not identical to that from SAS? for example: A,B and C are categorical variables,but the proportions of each level in each categorical variables are not balance. Y is a nominal variables(>=3 categories); To do
2005 Sep 08
1
Multinomial Logit and p-values
Hi, I am trying to obtain p-values for coefficient estimates in a multinomial logit model. Although I am able to test for significance using other methods (e.g., Wald statistics), I can't seem to get R to give me simple p-values. I am sure there is a very simple solution to this, but the R archives seem to have nothing on this issue. I would appreciate any help. Thanks in advance! Best,
2014 May 12
2
Duda_TEST DE WALD
Buenos días, Gracias Carlos, siguiendo el ejemplo que comentas, esto es lo que he introducido en el Scrip de RStudio: *library(xlsx)* *library(xlsxjars)* *library(rJava)* *library(aod)* *R<-read.csv("2002.CSV", sep=";", dec=",", header=T)* *attach(R)* *group<-gl(2,670,1340,labels= c("AVE", "Log.Imports.Value.in.1000.USD"))*
2011 Sep 23
1
p values in coxph()
Hi, I'm interested in building a Cox PH model for survival modeling, using 2 covariates (x1 and x2). x1 represents a 'baseline' covariate, whereas x2 represents a 'new' covariate, and my goal is to figure out where x2 adds significant predictive information over x1. Ideally, I could get a p-value for doing this. Originally, I thought of doing some kind of likelihood ratio
2008 Dec 13
2
Obtaining p-values for coefficients from LRM function (package Design) - plaintext
Sent this mail in rich text format before. Excuse me for this. ------------------------ Dear all, I'm using the lrm function from the package "Design", and I want to extract the p-values from the results of that function. Given an lrm object constructed as follows : fit <- lrm(Y~(X1+X2+X3+X4+X5+X6+X7)^2, data=dataset) I need the p-values for the coefficients printed by calling
2007 Feb 02
1
multinomial logistic regression with equality constraints?
I'm interested in doing multinomial logistic regression with equality constraints on some of the parameter values. For example, with categorical outcomes Y_1 (baseline), Y_2, and Y_3, and covariates X_1 and X_2, I might want to impose the equality constraint that \beta_{2,1} = \beta_{3,2} that is, that the effect of X_1 on the logit of Y_2 is the same as the effect of X_2 on the
2007 Jul 19
2
multinomial logit estimation
Good morning, I'd like to estimate a simple multinomial logit model in R (not a McFadden conditional logit). For instance, I'd like to estimate the probability of someone having one of eight titles in a company with the independent variables being the company characteristics. A binary logit is well documented. What about the multinomial? Thanks, Walt Paczkowski
2008 Jan 10
1
Fwd: multinomial regression for clustered data
Hello dear R-users, does any of you know a way to perform a multinomial regression with clustered data (i.e. repeated measurements)? I made the first analysis with Stata option vce cluster in the mlogit command but was looking for a similar functionality in R too... thanks all! niccolò [[alternative HTML version deleted]]
2007 Jun 11
1
epitools and R 2.5
At work after updating to R 2.5 I get an error using epitab from package epitools, when at home (R 2.4) I get no error. Could someone help me? Thanks Pietro Bulian Servizio di Onco-Ematologia Clinico-Sperimentale I.R.C.C.S. Centro di Riferimento Oncologico Via Franco Gallini 2 33081 Aviano (PN) - Italy phone: +39 0434 659 412 fax: +39 0434 659 409 e-mail: pbulian at cro.it (at work)
2014 May 10
2
Duda_TEST DE WALD
Hola a todos y todas, Gracias por vuestro apoyo en cantidad de preguntas anteriores, de nuevo os escribo para compartir una duda: Estoy trabajando con un modelo bien sencillo, es una regresión simple, pero me gustaría comprobar la significación estadística de cada uno de los coeficientes de regresión en el modelo. La idea es hacer un contraste de hipótesis. Me he descargado el paquete
2011 Nov 19
1
wald test: compare quantile regression estimators from different samples
Dear all, I am trying to compare the estimated coefficients of a quantile regression model between two different samples. It is a Wald test, but I cannot find one way to do that in R.The samples are collected conditional on a specific characteristic and I would like to test whether such characteristic indeed affect the estimators. The problem in the test anova.rq is that the response variable
2011 Sep 29
1
F and Wald chi-square tests in mixed-effects models
I have a doubt about the calculation of tests for fixed effects in mixed-effects models. I have read that, except in well-balanced designs, the F statistic that is usually calculated for ANOVA tables may be far from being distributed as an exact F distribution, and that's the reason why the anova method on "mer" objects (calculated by lmer) do not calculate the denominator df nor 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
2009 Nov 04
1
compute maximum likelihood estimator for a multinomial function
Hi there I am trying to learn how to compute mle in R for a multinomial negative log likelihood function. I am using for this the book by B. Bolker "Ecological models and data in R", chapter 6: "Likelihood an all that". But he has no example for multinomial functions. What I did is the following: I first defined a function for the negative log likelihood:
2012 Jul 28
4
quantreg Wald-Test
Dear all, I know that my question is somewhat special but I tried several times to solve the problems on my own but I am unfortunately not able to compute the following test statistic using the quantreg package. Well, here we go, I appreciate every little comment or help as I really do not know how to tell R what I want it to do^^ My situation is as follows: I have a data set containing a
2009 May 05
2
Stepwise logistic Regression with significance testing - stepAIC
Hello R-Users,   I have one binary dependent variable and a set of independent variables (glm(formula,…,family=”binomial”) ) and I am using the function stepAIC (“MASS”) for choosing an optimal model. However I am not sure if stepAIC considers significance properties like Likelihood ratio test and Wald test (see example below).     > y <- rbinom(30,1,0.4) > x1 <- rnorm(30) > x2
2005 Sep 05
2
model comparison and Wald-tests (e.g. in lmer)
Dear expeRts, there is obviously a general trend to use model comparisons, LRT and AIC instead of Wald-test-based significance, at least in the R community. I personally like this approach. And, when using LME's, it seems to be the preferred way (concluded from postings of Brian Ripley and Douglas Bates' article in R-News 5(2005)1), esp. because of problems with the d.f. approximation.
2008 Jun 20
1
omnibus LR in multinomial model
If one estimates a model using multinom, is it possible to perform the omnibus LR test ( the analogue to omnibus F in linear models ) using the output from multinom ? The residual deviance is there but I was hoping I could somehow pull out the deviance based on just using an intercept ? Sample code is below from the CAR book but I wasn't sure how to do it based on that example. Thanks
2012 May 26
2
Assessing interaction effects in GLMMs
Dear R gurus I am running a GLMM that looks at whether chimpanzees spend time in shade more than sun (response variable 'y': used cbind() on counts in the sun and shade) based on the time of day (Time) and the availability of shade (Tertile). I've included some random factors too which are the chimpanzee in question (Individual) and where they are in a given area (Zone). There are