MAPTRN - Projects points.

       To use MAPTRN or c_maptrn, load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c, preferably  in
       that order.

       The C-binding argument descriptions are the same as the FORTRAN argument descriptions.

       #include <ncarg/ncargC.h>

       void c_maptrn (float rlat, float rlon, float *uval,
       float *vval)

       Copyright (C) 1987-2009
       University Corporation for Atmospheric Research
       The use of this Software is governed by a License Agreement.

UNIX                                               March 1993                                     MAPTRN(3NCARG)

       RLAT and RLON
                   (input expressions, of type REAL) are the latitude and longitude, respectively, of a point on
                   the  globe.  RLAT  must  be  between -90. and +90., inclusive; RLON must be between -540. and
                   +540., inclusive.

       UVAL and VVAL
                   (output variables, of type REAL) define the point (UVAL,VVAL) that is the projection  in  the
                   u/v plane of (RLAT,RLON). The units of UVAL and VVAL depend on the projection.

                   If  the  point  is  not  projectable,  UVAL  is  returned  equal  to  1.E12.  If the point is
                   projectable, but outside the boundary of the map (as defined by the last call to  MAPSET  and
                   by  the  value of the parameter 'EL'), the routine MAPTRN, unlike MAPTRA, still returns its u
                   and v coordinates.

       Use the ncargex command to see the following relevant examples: cpex03, mpex09, bnchmk.

       See the ezmap man page for a description of all EZMAP error messages and/or informational messages.

       MAPTRN - Projects points.

       SUPCON is an alternate name for the routine MAPTRN.

       Online:  ezmap,  ezmap_params,  mapaci,  mapbla,  mapblm, mapdrw, mapeod, mapfst, mapgci, mapgrd, mapgrm,
       mapgtc, mapgti, mapgtl, mapgtr, mapint, mapiq, mapiqa, mapiqd, mapiqm,  mapit,  mapita,  mapitd,  mapitm,
       maplbl,  maplmb,  maplot,  mappos, maproj, maprs, maprst, mapsav, mapset, mapstc, mapsti, mapstl, mapstr,
       maptra, maptri, mapusr, mapvec, mpchln, mpfnme, mpgetc, mpgeti, mpgetl, mpgetr, mpglty,  mpiaty,  mpifnb,
       mpilnb,  mpiola,  mpiosa, mpipai, mpipan, mpipar, mpisci, mplnam, mplndm, mplndr, mplnri, mpname, mprset,
       mpsetc, mpseti, mpsetl, mpsetr, supmap, supcon, ncarg_cbind

       Hardcopy: NCAR Graphics Contouring and Mapping Tutorial

       CALL MAPTRN (RLAT, RLON, UVAL, VVAL)