NAME

       MAPGRM - Draws lines of latitude and longitude masked against an existing area map.

SYNOPSIS

       CALL MAPGRM (IAMA,XCRA,YCRA,MCRA,IAAI,IAGI,MNOG,ULPR)

C-BINDING SYNOPSIS

       #include <ncarg/ncargC.h>

       void c_mapgrm (int *iama, float *xcra, float *ycra,
       int mcra, int *iaai, int *iagi, int mnog,
       int (*ulpr)(float *xcra, float *ycra, int *ncs,
       int *iaai, int *iagi, int *nai))

DESCRIPTION

       IAMA        (an input/output array, dimensioned as specified in a call to the AREAS routine ARINAM, of
                   type INTEGER) is the array containing the area map against which lines of latitude and
                   longitude are to be masked. The area map must have been initialized by a call to ARINAM; it
                   may contain edges added to it by calling MAPBLA, as is the case in the example named
                   "eezmpa", or it may contain a different set of edges to create some other desired effect. For
                   example, an area map might be created that defines a region of interest, within which user
                   data is available and within which lines of latitude and longitude are to be drawn. For more
                   details, see the reference document for the package named AREAS.

       XCRA and YCRA
                   (scratch arrays, dimensioned at least MCRA, of type REAL) are to be used by MAPGRM in calls
                   to the AREAS routine ARDRLN; they will eventually be used in calls to the user-provided line-
                   processing routine ULPR.

       MCRA        (an input expression of type INTEGER) is the dimension of the arrays XCRA and YCRA.

       IAAI and IAGI
                   (scratch arrays, dimensioned at least NOGI, of type INTEGER) are to be used by MAPGRM in
                   calls to the AREAS routine ARDRLN; they will eventually be used in calls to the user-provided
                   line-processing routine ULPR. The mnemonics stand for "Integer Array of Area Identifiers" and
                   "Integer Array of Group Identifiers", respectively.

       NOGI        (an input expression of type INTEGER) is the dimension of the arrays IAAI and IAGI. The
                   mnemonic stands for "Number Of Group Identifiers (of edges in the area map)", which
                   determines the required dimension of IAAI and IAGI.

       ULPR        is the name of the user-supplied line-processing routine. It must be declared EXTERNAL in the
                   routine that calls MAPGRM, so that the compiler and loader will know that it is the name of a
                   routine to be called instead of a variable. The user routine ULPR will be called once for
                   each piece of a latitude/longitude line resulting from the masking process; it may decide to
                   draw (or to not draw) each such piece. ULPR will be called using a FORTRAN statement like

                        CALL ULPR (XCRA,YCRA,NCRA,IAAI,IAGI,NGPS)

                   where XCRA and YCRA are real arrays holding the normalized device coordinates of NCRA points
                   defining a polyline which is part of some latitude/longitude line and IAAI and IAGI are
                   integer arrays holding NGPS area-identifier/group-identifier pairs for the area within which
                   that piece of the line lies. In writing ULPR, the user may rely upon a SET call's having been
                   done which makes it possible to use normalized device coordinates in calls to routines like
                   CURVE, CURVED, GPL, etc. For more details, see the reference document for the package named
                   AREAS and, in particular, the description of the subroutine ARDRLN.

C-BINDING DESCRIPTION

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

USAGE

       The statement

            CALL MAPGRM (IAMA,XCRA,YCRA,MCRA,IAAI,IAGI,MNOG,ULPR)

       does the same thing as the statement

            CALL MAPGRD

       except that the grid lines are drawn using calls to MAPITM and MAPIQM, which does the masking of the
       lines against the area map defined by the arguments in the call and passes the pieces resulting from the
       masking process to a user-provided line-drawing routine.

EXAMPLES

       Use the ncargex command to see the following relevant examples: ccppole, cmpfil, cmpgrp, cmpitm, cmplab,
       cmpmsk, cmptit, cpex08, eezmpa, tezmpa, fcover, ffex03, ffex05.

ACCESS

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

SEE ALSO

       Online: ezmap, ezmap_params, mapaci, mapbla, mapblm, mapdrw, mapeod, mapfst, mapgci, mapgrd, mapgtc,
       mapgti, mapgtl, mapgtr, mapint, mapiq, mapiqa, mapiqd, mapiqm, mapit, mapita, mapitm, mapitd, maplbl,
       maplmb, maplot, mappos, maproj, 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.