Displaying 20 results from an estimated 7000 matches similar to: "aic for lrm"
2009 Jun 13
1
Insignificant variable improves AIC (multinom)?
Hi,
I am trying to specify a multinomial logit model using the multinom function from the nnet package. Now I add another independent variable and it halves the AIC as given by summary(multinom()). But when I call Anova(multinom()) from the car package, it tells me that this added variable is insignificant (Pr(>Chisq)=0.39). Thus, the improved AIC suggests to keep the variable but the Anova
2013 Jan 20
0
multinom and stargazer
I am trying to create a LaTex table based on a multinom (nnet) object using
the stargazer command.
I have created a small data frame to demonstration the problem:
data <- data.frame(age=1:21, hight=20:40,
ed=c(1,2,3,1,2,3,1,2,3,1,2,3,1,2,3,1,2,3,1,2,3))
data$ed <- as.factor(data$ed)
I then make a multinomial model using the command multinom from the nnet
package:
model <- multinom(ed ~
2011 Apr 08
1
multinom() residual deviance
Running a binary logit model on the data
df <- data.frame(y=sample(letters[1:3], 100, repl=T),
x=rnorm(100))
reveals some residual deviance:
summary(glm(y ~ ., data=df, family=binomial("logit")))
However, running a multinomial model on that data (multinom, nnet)
reveals a residual deviance:
summary(multinom(y ~ ., data=df))
On page 203, the MASS book says that "here the
2005 Apr 12
1
factors in multinom function (nnet)
Dear All:
I am interested in multinomial logit models (function multinon, library nnet) but I'm having troubles in choose whether to define the predictors as factors or not.
I had posted earlier this example (thanks for the reply ronggui):
worms<- data.frame(year= rep(2000:2004, c(3,3,3,3,3)),age=rep(1:3,5),
2010 Dec 15
0
Multinomial Analysis
I want to analyse data with an unordered, multi-level outcome variable, y. I am asking for the appropriate method (or R procedure) to use for this analysis.
> N <- 500
> set.seed(1234)
> data0 <- data.frame(y = as.factor(sample(LETTERS[1:3], N, repl = T,
+ prob = c(10, 12, 14))), x1 = sample(1:7, N, repl = T, prob = c(8,
+ 8, 9, 15, 9, 9, 8)), x2 = sample(1:7, N, repl =
2005 Apr 13
2
multinom and contrasts
Hi,
I found that using different contrasts (e.g.
contr.helmert vs. contr.treatment) will generate
different fitted probabilities from multinomial
logistic regression using multinom(); while the fitted
probabilities from binary logistic regression seem to
be the same. Why is that? and for multinomial logisitc
regression, what contrast should be used? I guess it's
helmert?
here is an example
2011 Apr 23
0
nnet Multinom output of ordered predictors
Hello,
I apologize if this seems like an obvious question, but I have been looking
everywhere and have yet to find an answer.
I am doing a multinomial regression with multinom() in the nnet package. I
have a 3 level ordered response (ordered()) variable and 4 predictors, 3 of
which are numerical and one which is an ordered factor (also ordered()) with
5 levels (a, b, c, d, e).
My question is in
2002 May 03
3
Regression models for ordinal responses ??
Hello list,
Is there any mean to fit models for ordinal response other than multinomial
polytomous ("multinom" from nnet ) and cumulative logit ("polr" from MASS)?
I am particularly interested in continuation-ratio model and
adjacent-category logit model. It is for the sake of epidemiology in
wild-living populations!
Many thanks,
Emmanuelle Fromont
2008 Dec 12
0
Help with a permutation test
Hello List and thanks in advance for all of your help,
I am trying implement a permutation test of a multinomial logistic
regression ('multinom' within the nnet package). In the end I want to
compare the parameter estimate from my data to the distribution of
randomized parameter estimates.
I have figured out how to permute my dependent variable (MNNUM) x number of
times, apply
2005 Jul 08
1
explained deviance in multinom
Hi:
I'm working with multinomial models with library nnet, and I'm trying to get the explained deviance (pseudo R^2) of my models.
I am assuming that:
pseudo R^2= 1 - dev(model) / dev (null)
where dev(model) is the deviance for the fitted model and dev(null) is the deviance for the null model (with the intercept only).
library(nnet)
full.model<- multinom(cbind(factor1,
2012 Jul 31
2
phantom NA/NaN/Inf in foreign function call (or something altogether different?)
Dear experts,
Please forgive the puzzled title and the length of this message - I
thought it would be best to be as complete as possible and to show the
avenues I have explored.
I'm trying to fit a linear model to data with a binary dependent
variable (i.e. Target.ACC: accuracy of response) using lrm, and
thought I would start from the most complex model (of which
"sample1.lrm1" is
2005 May 13
1
multinom(): likelihood of model?
Hi all,
I'm working on a multinomial (or "polytomous") logistic regression
using R and have made great progress using multinom() from the nnet
library. My response variable has three categories, and there are two
different possible predictors. I'd like to use the likelihoods of
certain models (ie, saturated, fitteds, and null) to calculate
Nagelkerke R-squared values for
2010 Mar 06
1
Robust SE for lrm object
I'm trying to obtain the robust standard errors for a multinomial ordered logit model:
mod6 <- lrm(wdlshea ~ initdesch + concap + capasst + qualrat + terrain,data=full2)
The model is fine but when I try to get the RSE I get an error.
coeftest(mod6, vcov = vcovHAC(mod6))
Error in match.arg(type) :
'arg' should be one of “ordinary”, “score”, “score.binary”, “pearson”,
2003 Jan 24
3
Multinomial Logit Models
Hi
I am wanting to fit some multinomial logit models (multinom command in
package nnet)
Is it possible to do any model checking techniques on these models
e.g. residual, leverage etc. I cannot seem to find any commands that
will allow me to do this.
Many thanks
----------------------
L.E.Gross
L.E.Gross at maths.hull.ac.uk
2004 Feb 23
3
library nnet
DeaR useRs:
I am looking for a function which fits a multinomial model and in Baron?s
page I find the function "multinom" in package "nnet" but this package is
deprecated.
I suppose that this function is now in other package but I can't find it.
Can you help me?
Thanks.
2006 Dec 21
1
multinom(nnet) analogy for biglm package?
I would like to perform a multinomial logistic regression on a large
data set, but do not know how. I've only thought of a few possibilities
and write to seek advice and guidance on them or deepening or expanding
my search.
On smaller data sets, I have successfully loaded the data and issued
commands such as:
length(levels(factor(data$response)))
[1] 6 # implies polychotomy
library(nnet)
2005 Apr 11
1
multi-class modeling
Hi,
Just wonder if someone could comment on using linear
discriminant analysis (LDA) vs. multinomial logistic
regression in multi-class classification/prediction
(nomial dependent variable, not ordinal)? What kind of
difference in results can I expect from the 2 methods,
which is better or more appropriate, or under what
condiditon should I used one instead of the other? And
is there other
2007 Nov 02
1
How to see source code of nnet package
Hi,
I am working on a project which needs a multinomial logit
regression. So I want to reference the code of
multinom in nnet package. I found nnet package is no longer in the
CRAN list. But I cannot find the source
code in R Core source code package either.
Anyone knows how to see the source code of nnet?
Luo
2005 Nov 21
2
Multinomial Nested Logit package in R?
Dear R-Help,
I'm hoping to find a Multinomial Nested Logit package in R. It would
be great to find something analogous to "PROC MDC" in SAS:
> The MDC (Multinomial Discrete Choice) procedure analyzes models
> where the
> choice set consists of multiple alternatives. This procedure
> supports conditional logit,
> mixed logit, heteroscedastic extreme value,
2006 Feb 22
2
does multinomial logistic model from multinom (nnet) has logLik?
I want to get the logLik to calculate McFadden.R2 ,ML.R2 and
Cragg.Uhler.R2, but the value from multinom does not have logLik.So my
quetion is : is logLik meaningful to multinomial logistic model from
multinom?If it does, how can I get it?
Thank you!
ps: I konw VGAM has function to get the multinomial logistic model
with logLik, but I prefer use the function from "official" R