xxxfor - Transforms input longitude and latitude to Easting and Northing for the xxx projection

SYNTAX

FUNCTION xxxfor (lon, lat, x, y)
    double lon;
    double lat;
    double *x;
    double *y;

PARAMETERS

lon (input, double)

Input longitude. Value given in radians.

lat (input, double)

Input latitude. Value given in radians.

x (output, double)

Easting value. Value given in meters.

y (output, double)

Northing value. Value given in meters.

DESCRIPTION

xxxfor() converts input longitude and latitude to the corresponding Easting and Northing for the xxx projection (xxx is replaced by the abbreviation of the projection). The following subroutines follow this general format:
     utmfor(lon, lat, x, y)     -- Universal Transverse Mercator (UTM) 
     stplnfor(lon, lat, x, y)   -- State Plane 
     alberfor(lon, lat, x, y)   -- Albers 
     lamccfor(lon, lat,x, y)    -- Lambert Conformal Conic
     merfor(lon, lat, x, y)     -- Mercator
     psfor(lon, lat, x, y)      -- Polar Stereographic
     polyfor(lon, lat, x, y)    -- Polyconic
     eqconfor(lon, lat, x, y)   -- Equidistant Conic
     tmfor(lon, lat, x, y)      -- Transverse Mercator (TM)
     sterfor(lon, lat, x, y)    -- Stereographic
     lamazfor(lon, lat, x, y)   -- Lambert Azimuthal
     azimfor(lon, lat, x, y)    -- Azimuthal Equidistant
     gnomfor(lon, lat, x, y)    -- Gnomonic
     orthfor(lon, lat, x, y)    -- Orthographic
     gvnspfor(lon, lat, x, y)   -- General Near Side Perspective
     sinfor(lon, lat, x, y)     -- Sinusoidal
     equifor(lon, lat, x, y)    -- Equirectangular
     millfor(lon, lat, x, y)    -- Miller
     vandgfor(lon, lat, x, y)   -- Van der Grinten
     omerfor(lon, lat, x, y)    -- Hotine Oblique Mercator (HOM)
     robfor(lon, lat, x, y)     -- Robinson
     somfor(lon, lat, x, y)     -- Space Oblique Mercator (SOM)
     alconfor(lon, lat, x, y)   -- Alaska Conformal
     goodfor(lon, lat, x, y)    -- Goode
     molwfor(lon, lat, x, y)    -- Mollweide
     imolwfor(lon, lat, x, y)   -- Interrupted Mollweide
     hamfor(lon, lat, x, y)     -- Hammer
     wivfor(lon, lat, x, y)     -- Wagner IV
     wviifor(lon, lat, x, y)    -- Wagner VII
     obleqfor(lon, lat, x, y)   -- Oblated Equal Area 
init_for() must be called once before calling any of the above subroutines. For example, if utmfor() is to be called, init_for() must be called setting the UTM projection, UTM zone, and ellipsoid. Then utmfor() may be called as many times as needed even if init_for() is called initializing another projection. The only exception is if init_for() is called initializing UTM with another zone or ellipsoid, then init_for() must be called again to perform the original conversion.

RETURN VALUE

xxxfor() returns

     E_SUCC (0)    --> Successful completion
     ERROR  (!= 0) --> An error was encountered

SPECIAL CONSIDERATIONS:

The xxxfor() call is for C only.