NAME

       MAPROJ - Sets the map projection to be used.

SYNOPSIS

       CALL MAPROJ (JPRJ, PLAT, PLON, ROTA)

C-BINDING SYNOPSIS

       #include <ncarg/ncargC.h>

       void c_maproj (char *jprj, float plat, float plon,
       float rota)

DESCRIPTION

       JPRJ        (an input expression, of type CHARACTER) defines the desired projection type.
                   All the possible values are two characters in length; these are the
                   possibilities:

                   The conic projection:

                       'LC' -  Lambert conformal conic with two standard parallels.

                   The azimuthal projections:

                       'ST' -  Stereographic.

                       'OR' -  Orthographic. The EZMAP parameter 'SA' will be zeroed. See the
                               note below.

                       'LE' -  Lambert equal area.

                       'GN' -  Gnomonic.

                       'AE' -  Azimuthal equidistant.

                       'SV' -  Satellite-view. If the EZMAP parameter 'SA' is less than or equal
                               to 1., it will be reset to 6.631 (the value for a satellite in a
                               geosynchronous orbit).  See the note below.

                   The cylindrical projections:

                       'CE' -  Cylindrical equidistant.

                       'ME' -  Mercator.

                       'MO' -  Mollweide-type.

                   Note: The orthographic and satellite-view projections have the same internal
                   identifier. The EZMAP parameter 'SA' determines which will be used. If a call
                   to MAPROJ selecting one or the other is followed by a call to MAPSTR resetting
                   'SA', it may have the effect of causing the other to be used.

       PLAT,PLON,ROTA
                   (input expressions, of type REAL) are angular quantities, in degrees. How they
                   are used depends on the value of JPRJ, as follows:

                   •   If JPRJ is not equal to 'LC': PLAT and PLON define the latitude and
                       longitude of the pole of the projection, the point on the globe which is
                       to project to the origin of the u/v plane. PLAT must be between -90.  and
                       +90., inclusive, positive in the northern hemisphere, negative in the
                       southern. PLON must be between -180. and +180., inclusive, positive to the
                       east, and negative to the west, of Greenwich.  ROTA is the angle between
                       the v axis and north at the origin.  It is taken to be positive if the
                       angular movement from north to the v axis is counter-clockwise, negative
                       otherwise. If the origin is at the north pole, "north" is considered to be
                       in the direction of PLON+180.  If the origin is at the south pole, "north"
                       is considered to be in the direction of PLON. For the cylindrical
                       projections, the axis of the projection is parallel to the v axis.

                   •   If JPRJ is equal to 'LC': PLON defines the central meridian of the
                       projection, and PLAT and ROTA define the two standard parallels. If PLAT
                       and ROTA are equal, a simpler conic projection, with one standard
                       parallel, is used.

C-BINDING DESCRIPTION

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

USAGE

       This routine allows you to set the current values of the EZMAP parameters 'PR', 'PT',
       'PN', and 'RO'.  For a complete list of parameters available in this utility, see the
       ezmap_params man page.

EXAMPLES

       Use the ncargex command to see the following relevant examples: ccpcica, ccpmap, ccpmovi,
       ccppole, ccpvp, colcon, cezmap1, cezmap2, cezmap3, cmpclr, cmpdd, cmpdrw, cmpel, cmpfil,
       cmpgrd, cmpgrp, cmpita, cmpitm, cmplab, cmplbl, cmplot, cmpmsk, cmpou, cmpsat, cmptit,
       cmptra, cmpusr, cpex01, cpex03, cpex08, cpex09, mpex01, mpex02, mpex04, mpex05, mpex06,
       mpex07, mpex09, mpex10, eezmpa, epltch, tezmap, tezmpa, fcover, ffex00, ffex02, ffex03,
       ffex05, fgkgtx, fngngdts, fpchiqu.

ACCESS

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

MESSAGES

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

SEE ALSO

       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, maprs, maprst, mapsav,
       mapset, mapstc, mapsti, mapstl, mapstr, maptra, maptri, maptrn, 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

COPYRIGHT

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