c
      subroutine pltorb(norb)
      include 'hrdi.h'
      character*56 toplab
      dimension viewport(4),viewmap(4)
      data ncalls/0/
c     data viewport /.15,.89,.26,.91/
      data viewport /.17,.87,.59,.94/
      data viewmap  /.17,.87,.08,.43/
      save ncalls,xmid
c
c Contour ut on x-axis, winds on y-axis
c
      ncalls = ncalls+1
      if (ncalls.eq.1) then
        call cpseti('MAP',0)
        call cpseti('SET',0)
        call cpsetc('HLT',' ')
        xmid = 0.5*(viewport(1)+viewport(2))
        call cpseti('ILP',0)
        call cpsetr('ILX',xmid)
        call cpsetr('ILY',-.16)
        call cpsetr('ILS',.016)
      endif
c
c Contour un:
c
      if (iplcon.gt.0) then
        write(toplab,"('HRDI UN (M/S)  UT=',f5.2,' TO ',f5.2,
     +    ' NPTS=',i3,25x)") ut(1),ut(norb),norb
        call set(viewport(1),viewport(2),viewport(3),viewport(4),
     +           slt(1),slt(norb),alt(1),alt(nalt),1)
        call cpsetr('XC1',slt(1))
        call cpsetr('XCM',slt(norb))
        call cpsetr('YC1',alt(1))
        call cpsetr('YCN',alt(nalt))
        call cpseti('MAP',0)
        call contour(un,mxrec,norb,nalt,0.,1.,0.)
        call labrect(slt,norb,alt,nalt,'LOCAL TIME (HRS)','ALT (KM)',0.)
        call wrlab(toplab(1:lenstr(toplab)),xmid,viewport(4)+.03,0.)
        call set(viewmap(1),viewmap(2),viewmap(3),viewmap(4),
     +    0.,1.,0.,1.,1)
        call maptrac(ut,glat,glon,norb,.04)
        call frame
        iframe = iframe+1
        write(6,"('  pltorb: frame ',i3,' Contour hrdi un (npts=',
     +    i3,')')") iframe,norb
c
c Contour vn:
c
        write(toplab,"('HRDI VN (M/S)  UT=',f5.2,' TO ',f5.2,
     +    ' NPTS=',i3,25x)") ut(1),ut(norb),norb
        lenlab = lenstr(toplab)
        call set(viewport(1),viewport(2),viewport(3),viewport(4),
     +           slt(1),slt(norb),alt(1),alt(nalt),1)
        call cpsetr('XC1',slt(1))
        call cpsetr('XCM',slt(norb))
        call cpsetr('YC1',alt(1))
        call cpsetr('YCN',alt(nalt))
        call cpseti('MAP',0)
        call contour(vn,mxrec,norb,nalt,0.,1.,0.)
        call labrect(slt,norb,alt,nalt,'LOCAL TIME (HRS)','ALT (KM)',0.)
        call wrlab(toplab(1:lenstr(toplab)),xmid,viewport(4)+.03,0.)
        call set(viewmap(1),viewmap(2),viewmap(3),viewmap(4),
     +    0.,1.,0.,1.,1)
        call maptrac(ut,glat,glon,norb,0.)
        call frame
        iframe = iframe+1
        write(6,"('  pltorb: frame ',i3,' Contour hrdi vn (npts=',
     +    i3,')')") iframe,norb
      endif
c
c Vector plot of un+vn:
c
      if (iplvec.gt.0) then
        write(toplab,"('HRDI UN+VN (M/S)  UT=',f5.2,' TO ',f5.2,
     +    ' NPTS=',i3,22x)") ut(1),ut(norb),norb
        call set(viewport(1),viewport(2),viewport(3),viewport(4),
     +           slt(1),slt(norb),alt(1),alt(nalt),1)
        call velvct(un,mxrec,vn,mxrec,norb,nalt,0.,0.,-1,0,0,1.e36)
        call labrect(slt,norb,alt,nalt,'LOCAL TIME (HRS)','ALT (KM)',0.)
        call wrlab(toplab(1:lenstr(toplab)),xmid,viewport(4)+.03,0.)
        call set(viewmap(1),viewmap(2),viewmap(3),viewmap(4),
     +    0.,1.,0.,1.,1)
        call maptrac(ut,glat,glon,norb,0.)
        call frame
        iframe = iframe+1
        write(6,"('  pltorb: frame ',i3,' Vectors hrdi un+vn (npts=',
     +    i3,')')") iframe,norb
      endif
c
c Map of orbit track:
c
c     if (iplmap.gt.0) then
c       call maptrac(ut,glat,glon,norb,0.)
c       call frame
c       iframe = iframe+1
c       write(6,"('  pltorb: frame ',i3,' map track')") iframe 
c     endif
c
      return
      end