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C;                                                                       ;
C;                Copyright (C)  1996                                    ;
C;        University Corporation for Atmospheric Research                ;
C;                All Rights Reserved                                    ;
C;                                                                       ;
C;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
C 
C    File:       pr01f.f
C 
C    Author: Lynn Hermanson
C            National Center for Atmospheric Research
C            PO 3000, Boulder, Colorado
C  
C    Date:       May 6, 1996
C 
C    Description:     Given an array of xaxis values and 
C                     an array of yaxis values, where each 
C                     x,y pair corresponds to one vertex or
C                     the location of one point, draw a
C                     square (a polyline), four points (asterisks)
C                     at the corners of a square (a polymarker), and
C                     a rectangular filled area (a polygon),on to
C                     a blank canvas (an empty default logLinPlot).

C                     Polylines, polymarkers, and polygons, are
C                     refered to as primitives.

C

      external NhlFAppClass
      external NhlFNcgmWorkstationClass
      external NhlFPSWorkstationClass
      external NhlFXWorkstationClass
      external NhlFMapPlotClass
      external NhlFVectorFieldClass
      external NhlFLogLinPlotClass
      external NhlFGraphicStyleClass

      integer appid,wid,cid,gsid
      integer rlist,ierr
      parameter(N=5)
      parameter(M=4)
      parameter(K=5)
      real X(N),Y(N)
      real U(M),V(M)
      real PX(K),PY(K)
      integer NCGM, X11, PS

      NCGM=0
      X11=1
      PS=0
C
C These are the polyline points /*a square*/
C

      X(1) = .3
      X(2) = .3
      X(3) = .5
      X(4) = .5
      X(5) = .3
      Y(1) = .3
      Y(2) = .5
      Y(3) = .5
      Y(4) = .3
      Y(5) = .3

C
C These are the polymarker points /*four corner points*/
C
      U(1) = .4
      U(2) = .4
      U(3) = .6
      U(4) = .6
      V(1) = .4
      V(2) = .6
      V(3) = .6
      V(4) = .4

C
C These are the polygon points /*a filled rectangle*/ 
C
      PX(1) = .7
      PX(2) = .7
      PX(3) = .8
      PX(4) = .8
      PX(5) = .7
      PY(1) = .2
      PY(2) = .8
      PY(3) = .8
      PY(4) = .2
      PY(5) = .2

C
C  Initialize the high level utility library
C
      call NhlFInitialize()

C Next,
C  create an application context. Set the app dir to the current directory
C  so the application looks for a resource file in the working directory.
C  In the following example default resources are used. 
C
      call NhlFRLCreate(rlist,'SETRL')
      call NhlFRLClear(rlist)
      call NhlFRLSetString(rlist,'appUsrDir','./',ierr)
      call NhlFCreate(appid,'pr01',NhlFappClass,
     1    NhlFDEFAULT_APP,rlist,ierr)

C  Choose to display output to an X11 workstation.(set above)*/

      if (NCGM.eq.1) then
C
C  Create a meta file workstation.
C
      call NhlFRLClear(rlist)
      call NhlFRLSetString(rlist,'wkMetaName','./pr01f.ncgm',ierr)
      call NhlFCreate(wid,'pr01Work',NhlFncgmWorkstationClass,
     1     appid,rlist,ierr)
    
      else if (X11.eq.1) then
C
C  Create an X workstation.
C
      call NhlFRLClear(rlist)
      call NhlFRLSetInteger(rlist,'wkPause','true',ierr)
      call NhlFCreate(wid,'pr01Work',NhlFxWorkstationClass,
     1            appid,rlist,ierr)
    

      else if (PS.eq.1) then
C
C  Create a PS workstation.
C
      call NhlFRLClear(rlist)
      call NhlFRLSetString(rlist,'wkPSFileName','./pr01.ps',ierr)
      call NhlFCreate(wid,'pr01Work',NhFlpsWorkstationClass,
     1    appid,rlist,ierr)

      endif    

C  Create a blank plot object to draw the primitives on.*/

      call NhlFRLClear(rlist)
      call NhlFCreate(cid,'canvas',NhlFlogLinPlotClass,
     1    wid,rlist,ierr)

C  Create a graphicPlot object consisting of, the default styles.*/
C  The graphicStyle object is NOT a stand-alone plot object. There
C    must exist some kind of plot object which has already been drawn
C    to place the primitives on.

      call NhlFRLClear(rlist)
      call NhlFCreate(gsid,'defaultstyle',NhlFgraphicStyleClass,
     1    wid,rlist,ierr)


C  Draw the shapes onto the blank logLinPlot object.
C  Signify end of frame.*/

      call NhlFDraw(cid,ierr)

C The last paramenter is the number of points required*/

      call NhlFNDCPolyline(cid, gsid, X, Y,5,ierr)
      call NhlFNDCPolymarker(cid, gsid, U, V,4,ierr)
      call NhlFNDCPolygon(cid, gsid, PX, PY,5,ierr)
      call NhlFFrame(wid,ierr)

C  Destroy all of the objects created, close the HLU library and exit.*/

      call NhlFDestroy(cid,ierr)
      call NhlFDestroy(wid,ierr)
      call NhlFDestroy(appid,ierr)
      call NhlFClose  

      stop
      end