anchor.diff:            write(output,*) (val(i),i=1,nvar)
             goto 101
     102 continue
  +
  +      write(0,*) idum
         END
   
   C----------------------------------------------------------------------C
  
positive.code: 
  C======================================================================C
  
        SUBROUTINE gcmdln(ifile,ofile,nvar)
        IMPLICIT NONE
        CHARACTER*80 ifile,ofile,tag
        INTEGER i,narg,nvar
        ifile = 'none'
        ofile = 'none'
        nvar = 1
        narg = iargc()
        if (narg.eq.0) call usage('')
  
negative.code: 
  C Initialize random number generator
        call raninit(idum)
        if (seed.gt.0) idum = -seed
  
  C Perturb input data
    101 read(input,*,end=102) (val(i),i=1,nvar),(dval(i),i=1,nvar)
  