*! version 1.0 93-07-22                 STB-18: sg23
program define bhatplot
 version 3.0
* This program draw the graph of log differences vs. class midpoints
* using as plot symbols the observation numbers in order to define
* the points to use for gaussian component determination.
* This routine is in accordance to Bhattacharya's method (1967)
* Optionaly, you can draw a subset of points for clarity with
* the [in range] option.
*syntax "bhatplot diflogvar midpoivar [in range]"
 local varlist "req ex min(2) max(2)"
 local in "opt"
 if "`2'"=="" {
      display "syntax: bhatplot diflogvar midpoivar [in range]"
      exit 
      }
 parse "`*'"
 quietly {
      tempvar touse 
      gen byte `touse'=0
      replace `touse'=1 `in'
      noisily graph `1' `2' if `touse', xlab ylab yline(0) s([_n]) 
      }
end