anchor.diff:        CHARACTER*40 ffmf,fltf,magf,haff,staf,trgf,dspf,stnf,stsf,norf,
        1             shrf,coulf,gmtf
         INTEGER flttyp,auto,xy,prog,long
  -      REAL*8 incr,depth
  +      REAL*8 incr,val
         INTEGER nflt,FMAX
         PARAMETER (FMAX=1500)
         REAL*8 evlo(FMAX),evla(FMAX),evdp(FMAX),str(FMAX),dip(FMAX),
  
positive.code: C Parse command line
  C----
        call gcmdln(ffmf,fltf,magf,haff,staf,trgf,dspf,stnf,stsf,norf,
       1            shrf,coulf,gmtf,flttyp,auto,incr,depth,xy,prog,long)
        call dbggcmdln(ffmf,fltf,magf,haff,staf,trgf,dspf,stnf,stsf,norf,
       2               shrf,coulf,gmtf,flttyp,auto,incr,depth,xy,prog,
       3               long)
  
  C----
  
negative.code:      1             slip,hylo,hyla)
  
  C----
  C Check for auto flag to define stations
  C----
         if (auto.ne.0) then
             if (auto.lt.10.or.val.gt.1d90.or.incr.gt.1d90) then
                 call usage('!! Error: -auto AB VAL INCR incorrect')
             endif
             call doauto(staf,nflt,evlo,evla,evdp,str,dx,dy,slip,
       1                 auto,val,incr,xy)
         endif
  
  C----
  C Check for input receiver, half-space, and target parameter files
  