From: Tate Avery <tate_sterling_avery_at_hotmail.com>

Date: Sat 13 Aug 2005 - 05:50:17 EST

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Sat Aug 13 05:56:31 2005

Date: Sat 13 Aug 2005 - 05:50:17 EST

Hello,

I am using polr(...) to generate a model. The summary shows the coefficients and the intercepts.

For example:

coefficient for x1 = c1

coefficient for x2 = c2

intercept A|B = i1

intercept B|C = i2

I can then run predict(..., type="p") with the model and see the odds for each factor.

For example:

A B C 1 0.3 0.5 0.2 2 0.4 0.1 0.5

What I really want to be able to do is take the 2 coefficients, the 2 intercepts, the x1 & x2 values and manually calculate the probabilities generated by predict().

I have been searching quite extensively for the underlying calculations that transform the polr output and the input variables into the final output odds. I have tried a number of dead-end roads so far.

So, if anyone has any information on how to do this or where I can find out, I would be extremely grateful.

Thank you for your time,

Tate Avery

R-help@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Sat Aug 13 05:56:31 2005

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