Hi I would like to analyse an ordinal categorical variable. I know how I can analyse a nominal categorical variable (with multinom or if there are only two levels with glm). Does somebody know which command I need in R to analyse an ordinal categorical variable? I want to describe the variable y with the variables x1,x2,x3 and x4. So my model looks like: y ~ x1+x2+x3+x4. y: ordinal factor variable with levels (never, rare, bychance, often). Thanks a lot in advance Thomas
Analysis of ordinal categorical data
4 messages · thsudler@swissonline.ch, John Fox, Brian Ripley +1 more
Dear Thomas, One approach to an ordinal response variable is the proportional-odds model, implemented in the MASS package as polr(). The proportional-odds assumption may not hold, however. I hope this helps, John
-----Original Message----- From: r-help-bounces at stat.math.ethz.ch [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of thsudler at swissonline.ch Sent: Wednesday, May 05, 2004 7:45 AM To: r-help at stat.math.ethz.ch Subject: [R] Analysis of ordinal categorical data Hi I would like to analyse an ordinal categorical variable. I know how I can analyse a nominal categorical variable (with multinom or if there are only two levels with glm). Does somebody know which command I need in R to analyse an ordinal categorical variable? I want to describe the variable y with the variables x1,x2,x3 and x4. So my model looks like: y ~ x1+x2+x3+x4. y: ordinal factor variable with levels (never, rare, bychance, often). Thanks a lot in advance Thomas
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On Wed, 5 May 2004, John Fox wrote:
One approach to an ordinal response variable is the proportional-odds model, implemented in the MASS package as polr(). The proportional-odds assumption may not hold, however.
And you can find out by comparing the fit with a multinom fit -- see the MASS scripts for a worked example.
Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595
1 day later
Thomas, R code for Agresti's book "Catagorical Data Analysis is available on Laura Thompson's web site. http://math.cl.uh.edu/~thompsonla/ You might find the book and the code helpful. Paul
On 5 May 2004, at 13:45, thsudler at swissonline.ch wrote:
Hi I would like to analyse an ordinal categorical variable. I know how I can analyse a nominal categorical variable (with multinom or if there are only two levels with glm). Does somebody know which command I need in R to analyse an ordinal categorical variable? I want to describe the variable y with the variables x1,x2,x3 and x4. So my model looks like: y ~ x1+x2+x3+x4. y: ordinal factor variable with levels (never, rare, bychance, often). Thanks a lot in advance Thomas
______________________________________________ R-help at stat.math.ethz.ch mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
P. B. Pynsent, Research & Teaching Centre, Royal Orthopaedic Hospital, Northfield, Birmingham, B31 2AP, U. K.