MAP_PROJ_INVERSE

The MAP_PROJ_INVERSE function transforms map coordinates from Cartesian (x, y) coordinates to longitude and latitude, using either the !MAP system variable or a supplied map projection variable.

Syntax

Result = MAP_PROJ_INVERSE (X [, Y] [, MAP_STRUCTURE=value] [, /RADIANS] )

Return Value

The result is a (2, n) array containing the longitude/latitude coordinates.

Arguments

X

An n-element vector containing the x values. If the Y argument is omitted, X must be a (2, n) array of X and Y pairs.

Y

An n-element vector containing y values. If this argument is omitted, X must be a (2, n) array of X and Y pairs.

Keywords

MAP_STRUCTURE

Set this keyword to a !MAP structure variable containing the projection parameters, as constructed by the MAP_PROJ_INIT. If this keyword is omitted, the !MAP system variable is used.

RADIANS

Set this keyword to indicate that the returned longitude and latitude coordinates should be expressed in radians. By default, returned coordinates are expressed in degrees.

Version History

Introduced: 5.6

See Also

MAP_PROJ_FORWARD, MAP_PROJ_INIT