#Chapter 12
#simulation to calculate power at a certain sample size with all continuous variables
bx=   #1
  bm=   #2
  sx=		#3
  sm=		#4
  sy=		#5
  c=		#8
  nsim=100  #number of simulations for the power analysis
alpha=0.05 #
result1=NULL
set.seed(1)
for (i in 1:nSims){
  pred=rnorm(n,0,sx)
  e1=rnorm(n,0,sm)
  e2=rnorm(n,0,sy)
  
  
  #continuous     
  m=a*pred+e1
  y=c*x+b*m+e2
  
  temp2<-mma(data.frame(m=m),y,pred=pred,mediator=1,
             jointm=list(n=1,j1=1),n2=100) 
  #m is forced in as a third-variable
  D=summary(temp2,plot=F,alpha=alpha)
  result1=rbind(result1,c(D$results$indirect.effect[[1]][,2]))}