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ncl_mxmy - Man Page

Retrieves the current pen position in the Plotter Address Unit (PAU) coordinate system.


Plotter Address Units (PAUs) are not being used in new NCAR Graphics routines; thus, MXMY is considered an obsolete routine.

The current recognized coordinate systems are GKS world coordinates, GKS normalized device coordinates, NCAR Graphics fractional coordinates, and NCAR Graphics user coordinates.  See the NCAR Graphics document "NCAR Graphics Fundamentals, UNIX Version" for a description of these coordinate systems.

MXMY continues to be provided for compatibility of early NCAR Graphics codes.  Frequently, consecutive calls to FRSTPT and MXMY were used to effectively convert from user coordinates to plotter coordinates; for this purpose, the functions KUPX and KUPY may be used instead.  If you are writing new code, you could keep track of the pen location through internal bookkeeping.  Better, though, would be to use fractional coordinates for the purposes to which plotter coordinates were put; the functions CFUX, CFUY, CUFX, and CUFY allow for conversions between user coordinates and fractional coordinates.

The following definition of the PAU Coordinate System is included for the purpose of interpreting and converting PAU codes:

The plotter coordinates of a point are integers IPX and IPY, where IPX is between 1 and 2**MX and IPY is between 1 and 2**MY.  MX and MY are internal parameters of SPPS; each has the default value 10. Values of MX and MY can be set by routine SETI and retrieved by routine GETSI.





(an output variable of type INTEGER) is the X coordinate of the pen position in PAUs.


(an output variable of type INTEGER) is the Y coordinate of the pen position in PAUs.


The routines CURVE, FRSTPT, LINE, PLOTIF, PLOTIT, POINT, POINTS, and VECTOR update the pen position for subsequent MXMY retrieval.  ALso, the routines PWRIT and WTSTR leave the pen position at the location specified by their first two arguments.


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

See Also

Online: curve, frstpt, line, plotit, point, points, pwrit, vector, seti, getsi, cpfx, cpfy, cpux, cpuy, kfpx, kfpy, kpmx, kpmy, kmpx, kmpy, kupx, kupy, spps, spps_converters

Hardcopy:   NCAR Graphics Fundamentals, UNIX Version; User's Guide for NCAR GKS-0A Graphics