====== Some results ====== structure(c(1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0.059, 0.072, 0.058, 0.046, 0.057, 0.065, 0.069, 0.043, 0.055, 0.054, 0.072, 0.059, 0.058, 0.05, 0.062, 0.059, 0.046, 0.073, 0.042, 0.051, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0.972, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0.814, 0.974, 1, 1, 1, 1, 1, 1, 1, 1, 0.146, 0.206, 0.288, 0.384, 0.452, 0.528, 0.593, 0.651, 0.69, 0.746, 0.291, 0.505, 0.665, 0.794, 0.897, 0.928, 0.952, 0.979, 0.987, 0.991, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0.442, 0.714, 0.896, 0.962, 0.976, 0.991, 0.997, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0.105, 0.188, 0.239, 0.33, 0.395, 0.474, 0.499, 0.544, 0.598, 0.65, 0.135, 0.2, 0.236, 0.318, 0.366, 0.432, 0.484, 0.52, 0.607, 0.622), .Dim = c(10L, 21L)) ====== R code ====== ## Monte Calor based power analysis for indirect effect using bootstrap ## by Zhiyong Zhang ## bootstrap confidence intervals ci.p<-function(par.boot, par0, cl=.95){ alpha<-(1-cl)/2 alpha<-c(alpha, 1-alpha) alpha<-sort(alpha) ci<-apply(par.boot, 2, quantile, prob=alpha, na.rm=TRUE) se.boot<-apply(par.boot, 2, sd, na.rm=TRUE) estimate<-par0 cbind(estimate, se.boot, t(ci)) } ci.norm<-function(par.boot, par0, cl=.95){ alpha<-(1-cl)/2 alpha<-c(alpha, 1-alpha) alpha<-sort(alpha) se.boot<-apply(par.boot, 2, sd, na.rm=TRUE) estimate<-par0 ci<-estimate+qnorm(alpha)%*%t(se.boot) dig <- max(2L, getOption("digits")) np<-length(alpha) qs <- paste(if (np < 100) formatC(100 * alpha, format = "fg", width = 1, digits = dig) else format(100 * alpha, trim = TRUE, digits = dig), "%", sep = "") ci.res<-cbind(estimate, se.boot, t(ci)) colnames(ci.res)<-c('estimate','se.boot', qs) ci.res } ci.bc1<-function(x, b, cl=.95){ n<-length(x) z0<-qnorm(sum(x0 | a[2]<0, 1, 0) } apply(res[, 3:4], 1, sig) } popPar<-function(object){ par.value<-object@ParTable$ustart for (i in 1:length(par.value)){ if (is.na(par.value[i])){ if (object@ParTable$op[i]=="~"){ par.value[i]<-0 }else{ par.value[i]<-1 } } } names(par.value)<-object@ParTable$label ## for indirect effec defined here for (i in 1:length(par.value)){ if (object@ParTable$op[i]==":="){ temp<-object@ParTable$rhs[i] temp<-gsub(' +','',temp) temp<-gsub('-','+', temp, fixed=TRUE) temp<-unlist(strsplit(temp, '+', fixed=TRUE)) m<-length(temp) temp.est<-0 par<-NULL for (j in 1:m){ temp1<-unlist(strsplit(temp[j], '*', fixed=TRUE)) par<-c(par, temp1) } ind.exp<-parse(text=object@ParTable$rhs[i]) par.list<-as.list(par.value[par]) par.value[i]<-eval(ind.exp, par.list) } } par.value } ## power function for analysis power.basic<-function(model, indirect=NULL, nobs, nrep=1000, alpha=.95, skewness=NULL, kurtosis=NULL, se="default", estimator="default", ...){ if (missing(model)) stop("A model is needed.") ## repeated the following for nrep times all.sig<-NULL all.par<-NULL all.se<-NULL all.cvg<-NULL model.indirect<-paste(model, "\n", indirect, "\n") ## Initial analysis for some model information newdata<-simulateData(model,sample.nobs=nobs,skewness=skewness,kurtosis=kurtosis, ...) temp.res<-sem(model.indirect, data=newdata, se=se, estimator=estimator, ...) par.value<-popPar(temp.res) for (i in 1:nrep){ ## Step 1: generate data newdata<-simulateData(model,sample.nobs=nobs,skewness=skewness,kurtosis=kurtosis, ...) ## Step 2: fit the model temp.res<-sem(model.indirect, data=newdata, se=se, estimator=estimator, ...) ## Step 3: Check significance idx <- 1:length( temp.res@ParTable$lhs ) temp.est<-temp.res@Fit@est[idx] temp.se<-temp.res@Fit@se[idx] temp.sig<-temp.est/temp.se crit<-qnorm(1-(1-alpha)/2) temp.sig.ind<-abs(temp.sig)>crit temp.sig.ind[!is.finite(temp.sig)]<-NA ## Step 4: Check the coverage ci.u<-temp.est+crit*temp.se ci.l<-temp.est-crit*temp.se temp.cvg<- (ci.u>par.value[idx]) & (ci.lpar.value[idx]) & (ci.res[,3] 1L) { scaled <- TRUE if(object$out@Options$test == "scaled.shifted") shifted <- TRUE else shifted <- FALSE } else { scaled <- FALSE shifted <- FALSE } t0.txt <- sprintf(" %-40s", "Esimation method") t1.txt <- sprintf(" %10s", object$out@Options$estimator) t2.txt <- ifelse(scaled, sprintf(" %10s", "Robust"), "") cat(t0.txt, t1.txt, t2.txt, "\n", sep="") t0.txt <- sprintf(" %-40s", "Standard error") t1.txt <- sprintf(" %10s", object$out@Options$se) cat(t0.txt, t1.txt, "\n", sep="") if (!is.null(object$info$bootstrap)){ t0.txt <- sprintf(" %-40s", "Number of requested bootstrap") t1.txt <- sprintf(" %10i", object$info$bootstrap) cat(t0.txt, t1.txt, "\n", sep="") } t0.txt <- sprintf(" %-40s", "Number of requested replications") t1.txt <- sprintf(" %10i", object$info$nrep) cat(t0.txt, t1.txt, "\n", sep="") t0.txt <- sprintf(" %-40s", "Number of successful replications") t1.txt <- sprintf(" %10i", nrow(object$results$estimates)) cat(t0.txt, t1.txt, "\n", sep="") cat("\n") # local print function print.estimate <- function(name="ERROR", i=1, z.stat=TRUE) { # cut name if (still) too long name <- strtrim(name, width=15L) txt <- sprintf(" %-15s %8.3f %8.3f %8.3f %8.3f %8.3f %8.3f\n", name, pop.value[i], est[i], mse[i], sd.est[i], power[i], cvg[i]) cat(txt) } est <- apply(object$results$estimates, 2, mean, na.rm=TRUE) sd.est <- apply(object$results$estimates, 2, sd, na.rm=TRUE) mse <- apply(object$results$se, 2, mean, na.rm=TRUE) power <- object$power pop.value<-object$pop.value cvg<-object$coverage object<-object$out for(g in 1:object@Data@ngroups) { ov.names <- lavaan:::vnames(object@ParTable, "ov", group=g) lv.names <- lavaan:::vnames(object@ParTable, "lv", group=g) # group header if(object@Data@ngroups > 1) { if(g > 1) cat("\n\n") cat("Group ", g, " [", object@Data@group.label[[g]], "]:\n\n", sep="") } # estimates header #txt <- sprintf("%-13s %12s %12s %8s %8s %8s\n", "", "True", "Estimate", "MSE", "SD", "Power") #cat(txt) cat(" True Estimate MSE SD Power Coverage\n") makeNames <- function(NAMES, LABELS) { multiB <- FALSE if(any(nchar(NAMES) != nchar(NAMES, "bytes"))) multiB <- TRUE if(any(nchar(LABELS) != nchar(LABELS, "bytes"))) multiB <- TRUE # labels? l.idx <- which(nchar(LABELS) > 0L) if(length(l.idx) > 0L) { if(!multiB) { LABELS <- abbreviate(LABELS, 4) LABELS[l.idx] <- paste(" (", LABELS[l.idx], ")", sep="") MAX.L <- max(nchar(LABELS)) NAMES <- abbreviate(NAMES, minlength = (13 - MAX.L), strict = TRUE) } else { # do not abbreviate anything (eg in multi-byte locales) MAX.L <- 4L } NAMES <- sprintf(paste("%-", (13 - MAX.L), "s%", MAX.L, "s", sep=""), NAMES, LABELS) } else { if(!multiB) { NAMES <- abbreviate(NAMES, minlength = 13, strict = TRUE) } else { NAMES <- sprintf(paste("%-", 13, "s", sep=""), NAMES) } } NAMES } NAMES <- object@ParTable$rhs # 1a. indicators ("=~") (we do show dummy indicators) mm.idx <- which( object@ParTable$op == "=~" & !object@ParTable$lhs %in% ov.names & object@ParTable$group == g) if(length(mm.idx)) { cat("Latent variables:\n") lhs.old <- "" NAMES[mm.idx] <- makeNames( object@ParTable$rhs[mm.idx], object@ParTable$label[mm.idx]) for(i in mm.idx) { lhs <- object@ParTable$lhs[i] if(lhs != lhs.old) cat(" ", lhs, " =~\n", sep="") print.estimate(name=NAMES[i], i) lhs.old <- lhs } cat("\n") } # 1b. formative/composites ("<~") fm.idx <- which( object@ParTable$op == "<~" & object@ParTable$group == g) if(length(fm.idx)) { cat("Composites:\n") lhs.old <- "" NAMES[fm.idx] <- makeNames( object@ParTable$rhs[fm.idx], object@ParTable$label[fm.idx]) for(i in fm.idx) { lhs <- object@ParTable$lhs[i] if(lhs != lhs.old) cat(" ", lhs, " <~\n", sep="") print.estimate(name=NAMES[i], i) lhs.old <- lhs } cat("\n") } # 2. regressions eqs.idx <- which(object@ParTable$op == "~" & object@ParTable$group == g) if(length(eqs.idx) > 0) { cat("Regressions:\n") lhs.old <- "" NAMES[eqs.idx] <- makeNames( object@ParTable$rhs[eqs.idx], object@ParTable$label[eqs.idx]) for(i in eqs.idx) { lhs <- object@ParTable$lhs[i] if(lhs != lhs.old) cat(" ", lhs, " ~\n", sep="") print.estimate(name=NAMES[i], i) lhs.old <- lhs } cat("\n") } # 3. covariances cov.idx <- which(object@ParTable$op == "~~" & !object@ParTable$exo & object@ParTable$lhs != object@ParTable$rhs & object@ParTable$group == g) if(length(cov.idx) > 0) { cat("Covariances:\n") lhs.old <- "" NAMES[cov.idx] <- makeNames( object@ParTable$rhs[cov.idx], object@ParTable$label[cov.idx]) for(i in cov.idx) { lhs <- object@ParTable$lhs[i] if(lhs != lhs.old) cat(" ", lhs, " ~~\n", sep="") print.estimate(name=NAMES[i], i) lhs.old <- lhs } cat("\n") } # 4. intercepts/means ord.names <- lavaan:::vnames(object@ParTable, type="ov.ord", group=g) int.idx <- which(object@ParTable$op == "~1" & !object@ParTable$lhs %in% ord.names & !object@ParTable$exo & object@ParTable$group == g) if(length(int.idx) > 0) { cat("Intercepts:\n") NAMES[int.idx] <- makeNames( object@ParTable$lhs[int.idx], object@ParTable$label[int.idx]) for(i in int.idx) { print.estimate(name=NAMES[i], i) } cat("\n") } # 4b thresholds th.idx <- which(object@ParTable$op == "|" & object@ParTable$group == g) if(length(th.idx) > 0) { cat("Thresholds:\n") NAMES[th.idx] <- makeNames( paste(object@ParTable$lhs[th.idx], "|", object@ParTable$rhs[th.idx], sep=""), object@ParTable$label[th.idx]) for(i in th.idx) { print.estimate(name=NAMES[i], i) } cat("\n") } # 5. (residual) variances var.idx <- which(object@ParTable$op == "~~" & !object@ParTable$exo & object@ParTable$lhs == object@ParTable$rhs & object@ParTable$group == g) if(length(var.idx) > 0) { cat("Variances:\n") NAMES[var.idx] <- makeNames( object@ParTable$rhs[var.idx], object@ParTable$label[var.idx]) for(i in var.idx) { if(object@Options$mimic == "lavaan") { print.estimate(name=NAMES[i], i, z.stat=FALSE) } else { print.estimate(name=NAMES[i], i, z.stat=TRUE) } } cat("\n") } # 6. latent response scales delta.idx <- which(object@ParTable$op == "~*~" & object@ParTable$group == g) if(length(delta.idx) > 0) { cat("Scales y*:\n") NAMES[delta.idx] <- makeNames( object@ParTable$rhs[delta.idx], object@ParTable$label[delta.idx]) for(i in delta.idx) { print.estimate(name=NAMES[i], i, z.stat=TRUE) } cat("\n") } } # ngroups # 6. variable definitions def.idx <- which(object@ParTable$op == ":=") if(length(def.idx) > 0) { if(object@Data@ngroups > 1) cat("\n") cat("Indirect effects:\n") NAMES[def.idx] <- makeNames( object@ParTable$lhs[def.idx], "") for(i in def.idx) { print.estimate(name=NAMES[i], i) } cat("\n") } }