pwr2ppl (version 0.5.0)

regint: Compute Power for Regression Interaction (Correlation/Coefficient Approach)

Description

Compute Power for Regression Interaction (Correlation/Coefficient Approach)

Usage

regint(
  Group1,
  Group2,
  sx1 = 1,
  sx2 = 1,
  sy1 = 1,
  sy2 = 1,
  nlow,
  nhigh,
  alpha = 0.05,
  Prop_n1 = 0.5,
  by = 2,
  Estimates = 1
)

Value

Power for Regression Interaction (Correlation/Coefficient Approach)

Arguments

Group1

Estimates (r or b) for Group 1

Group2

Estimates (r or b) for Group 2

sx1

Standard deviation of predictor, group 1 (defaults to 1)

sx2

Standard deviation of predictor, group 2 (defaults to 1)

sy1

Standard deviation of outcome, group 1 (defaults to 1)

sy2

Standard deviation of outcome, group 2 (defaults to 1)

nlow

starting sample size

nhigh

ending sample size

alpha

Type I error (default is .05)

Prop_n1

Proportion of Sample in First Group (defaults to equal sample sizes)

by

incremental increase in sample (e.g. nlow = 10, nhigh = 24, by = 2, produces estimates of 10, 12, and 14)

Estimates

1 for Correlations (default), 2 for coefficients

Examples

regint(Group1=-.26,Group2=.25, alpha=.05,Prop_n1=0.5,nlow=110, nhigh=140,by=2,Estimates=1)