Displaying 20 results from an estimated 3000 matches similar to: "colineraity among categorical variables (multinom)"
2013 Feb 25
1
frequency table-visualization for complex categorical variables
Dear R users,
I have three questions measuring close relationships.
The questions are same and the respondents put the answer in order.
I'd like to examine the pattern of answers and visualize it.
For example q1 (A,B,C,D,E) and q2 and q3 are the same. If the respondents
selects A B C (so BCA or BAC or CBA or CAB), I'd like to construct
frequency table for ABC and other combinations for
2012 Sep 15
5
create new variable with ifelse? (reproducible example)
Dear R users,
I have a reproducible data and try to create new variable "clo" is 1 if
know variable is equal to "very well" or "fairly well" and getalong is 4 or
5
otherwise it is 0.
rep_data<- read.table(header=TRUE, text="
id1 id2 know getalong
100000016_a1 100000016_a2 very well 4
100000035_a1 100000035_a2 fairly
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
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
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),
2012 Jan 05
2
difference of the multinomial logistic regression results between multinom() function in R and SPSS
Dear all,
I have found some difference of the results between multinom() function in
R and multinomial logistic regression in SPSS software.
The input data, model and parameters are below:
choles <- c(94, 158, 133, 164, 162, 182, 140, 157, 146, 182);
sbp <- c(105, 121, 128, 149, 132, 103, 97, 128, 114, 129);
case <- c(1, 3, 3, 2, 1, 2, 3, 1, 2, 2);
result <- multinom(case ~ choles
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 Nov 17
1
access standard errors from multinom model
Dear R users,
I'm using a multinomial LOGIT model to analyse choice behaviour of consumers
(as part of my masters thesis research).
Using the R documentation and search on the R website I have a working
script now.
Parameters are estimated and I can access them via
coefficients(multinom.out).
In order to see if the parameters are significant I like to access the
standard errors in the
2006 Jun 27
1
weights in multinom
Best R Help,
I like to estimate a Multinomial Logit Model with 10 Classes. The
problem is that the number of observations differs a lot over the 10
classes:
Class | num. Observations
A | 373
B | 631
C | 171
D | 700
E | 87
F | 249
G | 138
H | 133
I | 162
J | 407
Total: 3051
Where my data looks like:
x1 x2 x3 x4 Class
1 1,02 2 1 A
2 7,2 1 5 B
3 4,2 1 4 H
1 4,1 1 8 F
2 2,4 3 7 D
1 1,2 0 4 J
2 0,9
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
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
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,
2004 Sep 27
1
multinom object :way of plotting??
Dear all,
I'm fitting a multinom function to my dataset (multinom(outcome~age+K+D))
and I need to present my results on a poster. Does someone know a nice way
of doing that? I think I saw in an archive that you cannot plot a
multinom.object, is it true?
Thank you by advance for your help,
Cheers
Camille
2010 Mar 17
1
question about multinom function (nnet)
Dear All.
I have the following table that I want to analyze using multinom
function
freq segments sample
4271 Seg1 tumour
4311 Seg2 tumour
3515 Seg1 normal
3561 Seg2 normal
I want to compare model with both factors to the one where only sample
is present.
model1=multinom(freq~segments+sample,data=table)
model2=multinom(freq~ sample,data=table)
2006 Jul 05
2
Colinearity Function in R
Is there a colinearty function implemented in R? I
have tried help.search("colinearity") and
help.search("collinearity") and have searched for
"colinearity" and "collinearity" on
http://www.rpad.org/Rpad/Rpad-refcard.pdf but with no
success.
Many thanks in advance,
Peter Lauren.
2004 Jun 30
1
linear models and colinear variables...
Hi!
I'm having some issues on both conceptual and
technical levels for selecting the right combination
of variables for this model I'm working on. The basic,
all inclusive form looks like
lm(mic ~ B * D * S * U * V * ICU)
Where mic, U, V, and ICU are numeric values and B D
and S are factors with about 16, 16 and 2 levels
respectively. In short, there's a ton of actual
explanatory
2007 Jan 05
1
Efficient multinom probs
Dear R-helpers,
I need to compute probabilties of multinomial observations, eg by doing the
following:
y=sample(1:3,15,1)
prob=matrix(runif(45),15)
prob=prob/rowSums(prob)
diag(prob[,y])
However, my question is whether this is the most efficient way to do this.
In the call prob[,y] a whole matrix is computed which seems a bit of a
waste.
Is there maybe a vectorized version of dmultinom which
2001 Dec 12
2
Output from the multinom-function
Hello folks,
Let me first apologize: I'm not a professional nor a
mathematician, just an ordinary guy, fooling around
with the excellent R-package. I know the basic
principles behind statistics, but haven't read
anything more advanced than the ordinary first
probability and statistics courses.
Enough disclaimers? Good! I was examining the
multinom-function (in the nnet-package) the other
2006 Oct 24
2
colinearity?
I'm sorry to all those who are tired of seeing my email appear in need of
help. But, I've never coded in any program before, so this has been a
difficult process for me.
Is there a simple function to test for colinearity in R? I'm running a
logistic regression and a linear regression.
Thanks for the help!
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2012 Nov 06
2
R and SPSS
Hi group:
I have a data set, which has severe colinearity problem. While running linear regression in R and SPSS, I got different models. I am wondering if somebody knows how to make the two software output the same results. (I guess the way R and SPSS handling singularity is different, which leads to different models.)
Thanks.
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