power.SLR.rho {powerMediation}

Power for testing slope for simple linear regression

Description

Calculate power for testing slope for simple linear regression.

Usage

power.SLR.rho(n, 
              rho2, 
              alpha = 0.05, 
              verbose = TRUE)

Arguments

n

sample size.

rho2

square of the correlation between the outcome and the predictor.

alpha

type I error rate.

verbose

logical. TRUE means printing power; FALSE means not printing power.

Details

The power is for testing the null hypothesis \lambda=0 versus the alternative hypothesis \lambda\neq 0 for the simple linear regressions:

y_i=\gamma+\lambda x_i + \epsilon_i, \epsilon_i\sim N(0, \sigma^2_{e})

Value

power

power for testing if b_2=0.

delta

\sqrt{n}/\sqrt{1/\rho^2-1}.

Note

The test is a two-sided test. For one-sided tests, please double the significance level. For example, you can set alpha=0.10 to obtain one-sided test at 5% significance level.

Author(s)

Weiliang Qiu [e-mail]

References

Dupont, W.D. and Plummer, W.D.. Power and Sample Size Calculations for Studies Involving Linear Regression. Controlled Clinical Trials. 1998;19:589-601.

See Also

minEffect.SLR, power.SLR, ss.SLR.rho, ss.SLR.

Examples

  power.SLR.rho(n=100, rho2=0.6, alpha = 0.05, verbose = TRUE)