###==================================================
### Standard error function definition:
###==================================================

se <- function(x)
      {
        y <- x[!is.na(x)] # remove the missing values, if any
        sqrt(var(as.vector(y))/length(y))
}

## Create a PS file:

createPS <- function(filename){
postscript(file=filename,
           paper="a4",
           horizontal= TRUE,
           family="Times",
           pointsize=10)     
}

# Create a [row x col] multiplot 

multiplot <- function(row,col){
     op <- par(mfrow=c(row,col),pty="s")
   }

## Start-up comments:

.First <- function(){
    cat("\n   1. Function se loaded\n")
    cat("See .Rprofile in home directory for details.\n\n")
  }