SYNOPSISCALL MAPROJ (JPRJ, PLAT, PLON, ROTA)
C-BINDING SYNOPSIS#include <ncarg/ncargC.h>
void c_maproj (char *jprj, float plat, float plon,
(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' -
- 'OR' -
- Orthographic. The EZMAP parameter 'SA' will be zeroed. See the note below.
- 'LE' -
- Lambert equal area.
- 'GN' -
- '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' -
- 'MO' -
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.
- The conic projection:
(input expressions, of type REAL) are angular
quantities, in degrees. How they are used depends on the value of JPRJ,
- 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 DESCRIPTIONThe C-binding argument descriptions are the same as the FORTRAN argument descriptions.
USAGEThis 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.
EXAMPLESUse 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.
ACCESSTo use MAPROJ or c_maproj, load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c, preferably in that order.
MESSAGESSee the ezmap man page for a description of all EZMAP error messages and/or informational messages.
COPYRIGHTCopyright (C) 1987-2009
University Corporation for Atmospheric Research
The use of this Software is governed by a License Agreement.