Re: [R] Models with ordered and unordered factors

2011-11-16 Thread Catarina Miranda
Thanks a lot for your answers and reading suggestions, now I know my guess was completely wrong. I guess in my case it will be more informative to keep the unordered factors. That way I can know not only that days differ in general, but also get information on which day is differing from day 1. C

Re: [R] Models with ordered and unordered factors

2011-11-15 Thread Paul Johnson
On Tue, Nov 15, 2011 at 9:00 AM, Catarina Miranda wrote: > Hello; > > I am having a problems with the interpretation of models using ordered or > unordered predictors. > I am running models in lmer but I will try to give a simplified example > data set using lm. > Both in the example and in my rea

Re: [R] Models with ordered and unordered factors

2011-11-15 Thread Bert Gunter
... In addition, the following may also be informative. > f <- paste("day", 1:3) > contrasts(ordered(f)) .L .Q [1,] -7.071068e-01 0.4082483 [2,] -7.850462e-17 -0.8164966 [3,] 7.071068e-01 0.4082483 > contrasts(factor(f)) day 2 day 3 day 1 0 0 day 2 1

Re: [R] Models with ordered and unordered factors

2011-11-15 Thread Bert Gunter
Ordered factors use orthogonal polynomial contrasts by default. The .L and .Q stand for the linear and quadratic terms. Unordered factors use "treatment" contrasts although (they're actually not contrasts), that are interpreted as you described. If you do not know what this means, you need to do s

[R] Models with ordered and unordered factors

2011-11-15 Thread Catarina Miranda
Hello; I am having a problems with the interpretation of models using ordered or unordered predictors. I am running models in lmer but I will try to give a simplified example data set using lm. Both in the example and in my real data set I use a predictor variable referring to 3 consecutive days o

Re: [R] Models

2009-11-16 Thread Greg Snow
Val > Sent: Monday, November 09, 2009 4:08 PM > To: r-help@r-project.org > Subject: [R] Models > > Hi all, > I hope that there might be some statistician out there to help me for > a > possible explanation for the following simple question. > > Y1~ lm(y~ t1 + t2 +

Re: [R] Models for Discrete Choice in R

2009-11-10 Thread Frank E Harrell Jr
Iuri Gavronski wrote: Frank, I certainly can't speak for Emmanuel. I don't know his reasons. The reason I've posted this question is the fact that (as far as I understood), ordinal regression is based on logistic regression (or probit), and logistic regression expects a formula like dichotomous

Re: [R] Models for Discrete Choice in R

2009-11-10 Thread Iuri Gavronski
Frank, I certainly can't speak for Emmanuel. I don't know his reasons. The reason I've posted this question is the fact that (as far as I understood), ordinal regression is based on logistic regression (or probit), and logistic regression expects a formula like dichotomous ~ ratio1 + ratio2 + ...

[R] Models

2009-11-09 Thread Val
Hi all, I hope that there might be some statistician out there to help me for a possible explanation for the following simple question. Y1~ lm(y~ t1 + t2 + t3 + t4 + t5,data=temp) # oridnary linear model library(gam) Y2~ gam(y~ lo(t1) +lo(t2) +lo(t3) +lo(t4) +lo(t5),data=temp) # additive mode

Re: [R] Models for Discrete Choice in R

2009-11-09 Thread Frank E Harrell Jr
Emmanuel Charpentier wrote: Le dimanche 08 novembre 2009 à 19:05 -0600, Frank E Harrell Jr a écrit : Emmanuel Charpentier wrote: Le dimanche 08 novembre 2009 à 17:07 -0200, Iuri Gavronski a écrit : Hi, I would like to fit Logit models for ordered data, such as those suggested by Greene (2003)

Re: [R] Models for Discrete Choice in R

2009-11-09 Thread Emmanuel Charpentier
Le dimanche 08 novembre 2009 à 19:05 -0600, Frank E Harrell Jr a écrit : > Emmanuel Charpentier wrote: > > Le dimanche 08 novembre 2009 à 17:07 -0200, Iuri Gavronski a écrit : > >> Hi, > >> > >> I would like to fit Logit models for ordered data, such as those > >> suggested by Greene (2003), p. 736

Re: [R] Models for Discrete Choice in R

2009-11-08 Thread Frank E Harrell Jr
Emmanuel Charpentier wrote: Le dimanche 08 novembre 2009 à 17:07 -0200, Iuri Gavronski a écrit : Hi, I would like to fit Logit models for ordered data, such as those suggested by Greene (2003), p. 736. Does anyone suggests any package in R for that? look up the polr function in package MASS

Re: [R] Models for Discrete Choice in R

2009-11-08 Thread Emmanuel Charpentier
Le dimanche 08 novembre 2009 à 17:07 -0200, Iuri Gavronski a écrit : > Hi, > > I would like to fit Logit models for ordered data, such as those > suggested by Greene (2003), p. 736. > > Does anyone suggests any package in R for that? look up the polr function in package MASS (and read the releva

[R] Models for Discrete Choice in R

2009-11-08 Thread Iuri Gavronski
Hi, I would like to fit Logit models for ordered data, such as those suggested by Greene (2003), p. 736. Does anyone suggests any package in R for that? By the way, my dependent variable is ordinal and my independent variables are ratio/intervalar. Thanks, Iuri. Greene, W. H. Econometric Anal

Re: [R] U R ready for R! Now deploy your R models via cloud computing!

2009-01-22 Thread Ajay ohri
Hi Michael, Can you also build the PMML model on the cloud with R, paying for the processor ,memory usage. Any plans to extend the abilty to model, or is it just deploy PMML models on the cloud servers. Regards, Ajay http://www.decisionstats.com On Thu, Jan 22, 2009 at 4:29 AM, MZ wrote: > Fo

[R] U R ready for R! Now deploy your R models via cloud computing!

2009-01-21 Thread MZ
Following the recent NYT article about R, I thought this group is not only ready for R but ready to take it one step further. Got models in R? Deploy and score them in ADAPA in minutes on the Amazon EC2 cloud computing infrastructure! Zementis ( http://www.zementis.com ) has been working with the