powerreg.hlp.htm

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help for powerreg
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Linear regression power analysis

        powerreg , r2f(value) r2r(value) [ nvar(value) ntest(value) n(value)
              alpha(value) power(value) ]


Description

powerreg performs power analysis for linear regression models, treating the
predictor variables as fixed. If n() is specified powerreg computes power. If
n() is not specified then powerreg computes sample size.


powerlog Options

r2f R-squared for the full model (required).

r2r R-squared for the reduced model (required).

nvar total number of predictor variables (default = 1).

ntest number of predictors being tested (default = 1).

n total number of observations (optional).

alpha the alpha level (default = .05).

power nominal power level.

Examples

 . powerreg, r2f(.35) r2r(.25) nvar(2) ntest(1)
 . powerreg, r2f(.35) r2r(.25) nvar(2) ntest(1) n(90)

Authors

     Philip B. Ender
     UCLA Academic Technology Services
     enderatucla.edu

     Xiao Chen
     UCLA Academic Technology Services
     jingy1atucla.edu