GPROJECT Procedure

About Projection Parameters Data Sets

The PARMOUT= and PARMIN= options enable you to store and retrieve projection parameters from a data set. By using projection parameters, you can project two data sets in exactly the same way (for example, to project annotation points and a map separately).

Parameters data sets contain the following variables:

PROJ_MAP	identifies the map data set for the current observation.
PROJ_NAME	specifies the projection method
PROJ_OPTS	contains a space-delimited list of options.
PROJ_P1	specifies the value for the PARALLEL1 option.
PROJ_P2	specifies the value for the PARALLEL2 option.
PROJ_STDLAT	specifies the standard latitude for the equirectangular projection method.
PROJ_STDLONG	specifies the central meridian or standard longitude for the projection.
PROJ_XMIN	specifies the minimum X value for the projection.
PROJ_YMIN	specifies the minimum Y value for the projection.

Note: If any of the variable values are a missing value, then the values are calculated by the GPROJECT procedure.

Note: You can override the values of input projection parameters by specifying options in the PROC GPROJECT statement.

By default, the GPROJECT procedure automatically uses parameters from any data set named PROJPARM that is in the same library as the input data set. To disable input parameters, specify NOPARMIN.