simsem (version 0.2-8)

getPowerFit: Find power in rejecting alternative models based on fit indices criteria

Description

Find the proportion of fit indices that indicate worse fit than a specified cutoffs. The cutoffs may be calculated from getCutoff of the null model.

Usage

getPowerFit(altObject, cutoff, revDirec = FALSE, usedFit=NULL, ...)

Arguments

altObject

SimResult that indicates alternative model that users wish to reject

cutoff

Fit indices cutoffs from null model or users. This should be a vector with a specified fit indices names as the name of vector elements. This argument can be missing if the SimResult is specified in the altObj

revDirec

The default is to count the proportion of fit indices that indicates lower fit to the model, such as how many RMSEA in the alternative model that is worse than cutoffs. The direction can be reversed by setting as TRUE.

usedFit

Vector of names of fit indices that researchers wish to getCutoffs from. The default is to getCutoffs of all fit indices.

...

Additional arguments

Value

• List of power given different fit indices.

See Also

• getCutoffto find the cutoffs from null model.
• SimResultto see how to create simResult

Examples

loading.null <- matrix(0, 6, 1)
loading.null[1:6, 1] <- NA
LX.NULL <- simMatrix(loading.null, 0.7)
RPH.NULL <- symMatrix(diag(1))
RTD <- symMatrix(diag(6))
CFA.Model.NULL <- simSetCFA(LY = LX.NULL, RPS = RPH.NULL, RTE = RTD)
SimData.NULL <- simData(CFA.Model.NULL, 500)
SimModel <- simModel(CFA.Model.NULL)
# We make the examples running only 5 replications to save time.
# In reality, more replications are needed.
Output.NULL <- simResult(5, SimData.NULL, SimModel)
Cut.NULL <- getCutoff(Output.NULL, 0.95)

u79 <- simUnif(0.7, 0.9)
loading.alt <- matrix(0, 6, 2)
loading.alt[1:3, 1] <- NA
loading.alt[4:6, 2] <- NA
LX.ALT <- simMatrix(loading.alt, 0.7)
latent.cor.alt <- matrix(NA, 2, 2)
diag(latent.cor.alt) <- 1
RPH.ALT <- symMatrix(latent.cor.alt, "u79")
CFA.Model.ALT <- simSetCFA(LY = LX.ALT, RPS = RPH.ALT, RTE = RTD)
SimData.ALT <- simData(CFA.Model.ALT, 500)
Output.ALT <- simResult(5, SimData.ALT, SimModel)
getPowerFit(Output.ALT, cutoff=Cut.NULL)
Rule.of.thumb <- c(RMSEA=0.05, CFI=0.95, TLI=0.95, SRMR=0.06)
getPowerFit(Output.ALT, cutoff=Rule.of.thumb, usedFit=c("RMSEA", "CFI", "TLI", "SRMR"))

Output.NULL2 <- simResult(NULL, SimData.NULL, SimModel, n=seq(50, 500, 50))
Output.ALT2 <- simResult(NULL, SimData.ALT, SimModel, n=seq(50, 500, 50))
getPowerFit(Output.ALT2, nullObject=Output.NULL2, nVal=250)