KUMX(3NCARG)

💖 KUMX — the NCAR Graphics glow-up 💖

okay bestie, welcome to KUMX, a whole vibe from the NCAR Graphics manual. She's one little function, but she brought her entire friend group, so buckle up 🎀

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✨ NAME ✨

KUMX — converts from user coordinates to metacode coordinates. that's it, that's her whole job, and she does it flawlessly 💅

but wait, there's more, because this page is actually the home of spps_converters — a whole set of functions, each of which transforms a coordinate from one of the NCAR Graphics coordinate systems to another. the complete list of functions is as follows, no cap:

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.

twenty-four icons. a whole girl group 🌈

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🦋 STATUS 🦋

ngl, here's the tea: Plotter Address Units (PAUs) and Metacode Units (MUs) are no longer used in NCAR Graphics. so every function with either an M or a P as the second or third letter of the function name is considered obsolete. they're the retired members of the group, we still love them, we do not use them 😭

the current recognized coordinate systems, aka the main characters, are:

• GKS world coordinates
• GKS normalized device coordinates
• NCAR Graphics fractional coordinates
• NCAR Graphics user coordinates

if you want the full lore on these coordinate systems, go read the NCAR Graphics document "NCAR Graphics Fundamentals, UNIX Version". it's giving required reading 📚

so here's why the obsolete stuff is even documented — the following definitions of the PAU coordinate system and the MU coordinate system are provided for the purpose of interpreting and converting codes which use PAUs or MUs:

• 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. values of MX and MY can be set by calling the routines SETI or SETUSV and retrieved 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.

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🌸 SYNOPSIS 🌸

current, aka the ones you should actually be using ✨:

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

obsolete, aka the vintage collection 🕰️:

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)

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💜 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)

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⭐ DESCRIPTION ⭐

okay so let's decode the naming scheme, because it's lowkey a cipher and honestly? iconic 🕵️‍♀️

• RX — an input expression of type REAL, and she's an X coordinate in the coordinate system specified by the second letter of the function name. 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, and she's a 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, bestie. they represent input expressions of type INTEGER, specifying the X and Y coordinates of a point in either PAUs or MUs (depending on the second letter of the function name).

and now, the letter-by-letter breakdown, because the way this is structured? obsessed 💅

• 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 (the latter only happens for some of the obsolete ones). this conforms to the usual FORTRAN convention for implicit typing.
• 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.

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🫶 C-BINDING DESCRIPTION 🫶

the C-binding argument description is the same as the FORTRAN argument description. no notes, same energy, periodt 💖

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🔥 EXAMPLES 🔥

use the ncargex command to see the following relevant examples which use coordinate converters:

• mpex10
• cbex10
• sfex02
• epltch

and fr fr, this next bit is handy:

ncargex -n mpex10

that command 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. go look at it, it's right there, she's waiting for you 🥰

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👑 ACCESS 👑

there were 24 conversion functions in the original set. these functions (12 for the X coordinate of a point, and 12 for the Y coordinate) allowed one to convert between any combination of PAUs, MUs, fractional coordinates, and user coordinates. a whole era 🌈

but PAUs and MUs are now obsolete, so only four of the conversion functions are still pertinent:

• CFUX and CFUY allow one to convert the X and Y coordinates of a point from the fractional system to the user system
• CUFX and CUFY do the opposite

to use any of the conversion routines, load the load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c, preferably in that order. (yes, the original really does say "load the load" — we're keeping it exactly as-is, no editing the source material, that's the rules 💀)

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🧚 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

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💀 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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okay that's the whole page, you ate it, you understood it, you're basically a coordinate conversion girlie now 🌟

this was SPPS_converters(3NCARG), from the UNIX manual, dated March 1993 — yeah she's vintage but she's still serving 💅 bye bestie, love u, go convert some coordinates 🦋💖