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Logistic regression power analysis

        powerlog , p1(value) p2(value) [ rsq(value) alpha(value) help ]


Description

powerlog performs power analysis for logistic regression designs with a
continuous predictor variable.  Multiple predictor models can be accomodated
using the rsq option.


powerlog Options

p1 estimated probability of a 1 at the mean of the predictor (required).

p2 estimated probability of a 1 at the mean + 1 sd of the predictor (required).

rsq squared multiple correlation of the predictor with all other predictors.
    Use rsq=0 for a 1-predictor model. (default = 0).

alpha the alpha level (default = .05).

help displays explanation of terms.

Examples

 . powerlog, p1(.25) p2(.35) alpha(.01) help
 . powerlog, p1(.25) p2(.35) rsq(.4)

Acknowledgements

 Based on (copied from) on the SAS macro program, POWERLOG.SAS (version 1.1),
     Created 1998, revised 2002, by Michael Friendly <FRIENDLY@YorkU.CA>.

Author

     Philip B. Ender
     UCLA Academic Technology Services
     enderatucla.edu