#
# Written by:
# -- 
# John L. Weatherwax                2009-04-21
# 
# email: wax@alum.mit.edu
# 
# Please send comments and especially bug reports to the
# above email address.
# 
#-----

tmean <- function(x,p=0.2){
  n  = length(x)
  if( n==0 ) return(x)
  g  = floor(p*n)
  xs = sort(x)
  xs = tail(xs,-g) # drop the first "g" elements
  xs = head(xs,-g) # drop the last "g" elements
  m  = mean(xs)
  return(m)
}