[R] Why replacement has length zero? And How can I fix it?

[soon yi]

Hi 

for the loop section runif needs curved brackets

Try

IAP <-NA
for (i in 1:Sample.Size){ 
	if (DataSet$SES[i]>0)   { 
		IAP[i] <-  ifelse(runif(1)>0.75, 1, 0) # High SES, higher chance to be in
Treatment # 
 		} 
	else  { 
 		IAP[i] <- ifelse(runif(1)<=0.25, 1, 0) # Low SES, lower chance to be in
Treatment # 
		 } 
	} # End loop # 
IAP




IAP 
zjiaqi19880219 wrote
> Hi, all,
> 
> I am working on a project to run a simulation. I am now working on the
> main body of the simulation body, I generate the data and all work well
> before I identify a variable "IAP", there is always an error message as
> "replacement has length zero", and I do not know how to fix it. Can anyone
> help?
> 
> Here is the code:
> 
> library (mvtnorm)
> 
> options(digits=2)
> 
> # Set variable name #
> namelist1 <- c("Age", "Gender", "SES", "ISS", "IQTe", "PreTe")
> 
> # Generate Data #
> Sample.Size <- 10 # Variable Sample Size #
> CorMat <- matrix(c(1.0 ,0.0 ,0.0 , 0.5, 0.2, 0.5,
> 					0.0, 1.0 ,0.0, 0.0, 0.0, 0.0,
> 					0.0 ,0.0 ,1.0, 0.5, 0.4, 0.5,
> 					0.5, 0.0, 0.5, 1.0, 0.4, 0.7,
> 					0.2, 0.0, 0.4, 0.4, 1.0, 0.9,
> 					0.5, 0.0, 0.5, 0.7, 0.9, 1.0),ncol=6) # Correlation Matrix #
> 
> DataSet <- rmvnorm(Sample.Size, mean=c(0,0,0,0,0,0), sigma=CorMat) # Draw
> Sample.Size covariate set all mean 0 #
> DataSet <- as.data.frame(DataSet)
> names(DataSet) <- namelist1
> DataSet
> 
> # For Treatment IAP #
> IAP <- matrix(0, nrow=Sample.Size)
> for (i in 1:Sample.Size){
> 	IAP[i] <- if (DataSet$SES>0)
> 	{
> 		ifelse(runif[1]>0.75, 1, 0) # High SES, higher chance to be in Treatment
> #
> 	}
> 	IAP[i] <- if (DataSet$SES<=0)
> 	{
> 		ifelse(runif[1]<=0.25, 1, 0) # Low SES, lower chance to be in Treatment
> #
> 	}
> } # End loop #
> IAP
> 
> Error in IAP[i] <- if (DataSet$SES > 0) { : replacement has length zero
> In addition: Warning message:
> In if (DataSet$SES > 0) { :
>   the condition has length > 1 and only the first element will be used
> 
> Thanks!





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