NGRITD(3NCARG)

💫 NGRITD — bestie, we're rotating a point 💫

okay so this is a page from the NCAR GRAPHICS manuals, section 3NCARG, and it's all about NGRITD. like, the name says it: N-G-RIT-D, we're out here spinning a point around an axis by some angle. and honestly? slay. 💅

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✨ NAME ✨

NGRITD — give it the coordinates of a point and it performs a rotation of that point about a specified axis by a specified angle. that's it, that's the whole vibe. 🌀

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✨ SYNOPSIS ✨

CALL NGRITD (IAXS,ANGL,UCRD,VCRD,WCRD)

🌸 C-BINDING SYNOPSIS 🌸

#include <ncarg/ncargC.h>

void c_ngritd(int iaxs, float angl, float *ucrd, float *ycrd,
float *wcrd)

(no fr, that's exactly how it's written, ycrd and all — we do not editorialize, we transcribe. 🫶)

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✨ DESCRIPTION ✨

• IAXS — an input expression of type INTEGER. this is the axis you're rotating around. 1 means the U axis, 2 means the V axis, and 3 means the W axis. pick your fighter. 🎀
• ANGL — an input expression of type REAL. the magnitude, in degrees, of the rotation angle. it's giving "how much do we spin". 🔥
• UCRD — an input/output variable of type REAL. the U coordinate of the point being rotated. (input and output bestie, she comes back different.) ✨
• VCRD — an input/output variable of type REAL. the V coordinate of the point being rotated. 💜
• WCRD — an input/output variable of type REAL. the W coordinate of the point being rotated. 💖

🌈 C-BINDING DESCRIPTION 🌈

the C binding argument descriptions are the same as the FORTRAN argument descriptions. literally identical. no notes. 👑

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✨ USAGE ✨

so who's actually using this? NGGCOG and NGGSOG, that's who. this routine is used by them to effect the rotations that are used to generate an object of a specified shape at a specified point on the surface of the globe. 🌍 iconic behavior tbh.

NGRITD assumes that the UVW coordinate system is right-handed. 🫱

positive values of ANGL give counter-clockwise rotations and negative values of ANGL give clockwise rotations. 🔄

and here's the cheat sheet, memorize it, it's on the test:

• when IAXS = 1, ANGL = 90 carries the positive V axis into the positive W axis
• when IAXS = 2, ANGL = 90 carries the positive W axis into the positive U axis
• when IAXS = 3, ANGL = 90 carries the positive U axis into the positive V axis

(cyclic vibes. the axes are passing the aux around. 💫)

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✨ EXAMPLES ✨

use the ncargex command to see the following relevant example: cpex10.

go look at it. it's right there. 🙈

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✨ ACCESS ✨

to use NGRITD or c_ngritd, load the NCAR Graphics libraries ncarg, ncarg_gks, and ncarg_c, preferably in that order. the order matters bestie, don't be chaotic. 🔗

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✨ MESSAGES ✨

None.

like literally none. silence. the routine is unproblematic and says nothing. 🤐✨

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✨ SEE ALSO ✨

Online: nggcog(3NCARG), nggsog(3NCARG).

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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 one tiny seriousness moment: the license agreement thing is real and it governs how you use this software, so read it, don't just vibe past it. 🫶

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and that's the whole page, bestie!! 🌸🦋 this was the UNIX rendering of the NGRITD(3NCARG) manual page, dated March 1993. yes, 1993. she's vintage, she's legacy, she's still rotating points and she ate. 💅✨👑