KMPX(3NCARG)

✨ NAME ✨

hi bestie 🫶 welcome to KMPX(3NCARG), straight out of the NCAR GRAPHICS corner of the universe. we're in manual section 3NCARG and this page is giving "coordinate converter" energy:

• KMPX — converts from metacode coordinates to plotter address unit coordinates.

that's it, that's the whole flex. periodt. 💅

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and now, the sequel nobody asked for but literally everyone needed — SPPS_converters(3NCARG), also NCAR GRAPHICS 💖

🌸 NAME 🌸

• spps_converters — a whole squad of functions, each one transforming a coordinate from one of the NCAR Graphics coordinate systems into another. the complete roster is literally this: CFUX, CFUY, CMFX, CMFY, CMUX, CMUY, CPFX, CPFY, CPUX, CPUY, CUFX, CUFY, KFMX, KFMY, KFPX, KFPY, KMPX, KMPY, KPMX, KPMY, KUMX, KUMY, KUPX, and KUPY.

💀 STATUS 💀

okay so here's the tea ☕

• Plotter Address Units (PAUs) and Metacode Units (MUs) are no longer used in NCAR Graphics; thus, literally every function with either an M or a P as the second or third letter of its name is considered obsolete. rip 🪦
• the coordinate systems that ARE still recognized rn are GKS world coordinates, GKS normalized device coordinates, NCAR Graphics fractional coordinates, and NCAR Graphics user coordinates. if you want the full descriptions of these, go read the NCAR Graphics document "NCAR Graphics Fundamentals, UNIX Version". 📖
• the following definitions of the PAU coordinate system and the MU coordinate system are here purely so you can interpret and convert codes that still use PAUs or MUs (iykyk):
  • 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 a default value of 10. you can set the values of MX and MY by calling the routines SETI or SETUSV, and retrieve them by calling the routines GETSI or GETUSV.
  • the metacode coordinates of a point are integers IMX and IMY between 0 and 32767 inclusive. the area addressed is a square in a "metacode space" that is usually mapped into a square subset of the addressable area of the plotting device. metacode coordinates were used in calls to the routine PLOTIT and are returned in calls to FL2INT.

🎀 SYNOPSIS 🎀

Current:

X = CFUX (RX),  Y = CFUY(RY)
X = CUFX (RX),  Y = CUFY(RY)

Obsolete:

X = CMUX (IX),  Y = CMUY(IY)
X = CPUX (IX),  Y = CPUY(IY)
X = CMFX (IX),  Y = CMFY(IY)
X = CPFX (IX),  Y = CPFY(IY)
I = KFMX (RX),  J = KFMY(RY)
I = KUMX (RX),  J = KUMY(RY)
I = KFPX (RX),  J = KFPY(RY)
I = KUPX (RX),  J = KUPY(RY)
I = KPMX (IX),  J = KPMY(IY)
I = KMPX (IX),  J = KMPY(IY)

🌈 C-BINDING SYNOPSIS 🌈

#include <ncarg/ncargC.h>

float c_cfux (float rx)

float c_cfuy (float ry)

float c_cufx (float rx)

float c_cufy (float ry)

🌸 DESCRIPTION 🌸

okay bestie, let's decode the alphabet soup 🔤

• RX — an input expression of type REAL, and it's an X coordinate living in the coordinate system specified by the second letter of the function name. so in a reference to CFUX, RX is a fractional X coordinate; in a reference to CUFX, RX is a user X coordinate.
• RY — an input expression of type REAL, an Y coordinate in the coordinate system specified by the second letter of the function name. in a reference to CFUY, RY is a fractional Y coordinate; in a reference to CUFY, RY is a user Y coordinate.
• IX and IY — these only show up as arguments in references to some of the obsolete functions. they're input expressions of type INTEGER, specifying the X and Y coordinates of a point in either PAUs or MUs (which one depends on the second letter of the function name).
• the first letter of the function name is a C if the result is of type REAL and a K if the result is of type INTEGER (and the K situation only happens for some of the obsolete ones). this conforms to the usual FORTRAN convention for implicit typing, slay. 👑
• the second letter of the function name specifies the coordinate system of the argument.
• the third letter of the function name specifies the coordinate system of the functional result. in references to CFUX and CFUY, the result is in the user system; in references to CUFX and CUFY, the result is in the fractional system.
• the fourth letter of the function name is an X or a Y, depending on whether an X or a Y coordinate is being converted.

💜 C-BINDING DESCRIPTION 💜

ngl this one's short and sweet: the C-binding argument description is the same as the FORTRAN argument description. copy-paste energy. 🫶

🔥 EXAMPLES 🔥

wanna see it in action? use the ncargex command to peek at the following relevant examples which use coordinate converters: mpex10, cbex10, sfex02, epltch.

and this command right here:

ncargex -n mpex10

will load the driver mpex10.f into your current working directory 🎀 where you can examine the file using a local editor, or the UNIX more command. iconic.

👑 ACCESS 👑

• there were 24 conversion functions in the original set — 12 for the X coordinate of a point, and 12 for the Y coordinate — and they let you convert between any combination of PAUs, MUs, fractional coordinates, and user coordinates. BUT: PAUs and MUs are obsolete now, so only four of the conversion functions are still pertinent: CFUX and CFUY let you convert the X and Y coordinates of a point from the fractional system to the user system, while CUFX and CUFY do the opposite. 🦋
• to use any of the conversion routines, load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c — preferably in that order. ⭐

🌟 SEE ALSO 🌟

Online: cfux, cfuy, cmfx, cmfy, cmux, cmuy, cpfx, cpfy, cpux, cpuy, cufx, cufy, kfmx, kfmy, kfpx, kfpy, kmpx, kmpy, kpmx, kpmy, kumx, kumy, kupx, kupy, spps, ncarg_cbind

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

🎀 COPYRIGHT 🎀

Copyright (C) 1987-2009 University Corporation for Atmospheric Research

The use of this Software is governed by a License Agreement.

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and that's a wrap bestie 💖 this was KMPX(3NCARG) and SPPS_converters(3NCARG) from NCAR GRAPHICS, on UNIX, dated March 1993 ✨ go forth and convert some coordinates, you absolute legend 👑