CSA2LS(3NCARG)

💖 CSA2LS 💖

okay so bestie, welcome to CSA2LS from the NCAR GRAPHICS manual, section 3NCARG — it's giving cubic spline approximation, simple entry for two-dimensional input, list output and honestly? she's a whole vibe. 🎀

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✨ SYNOPSIS ✨

CALL CSA2LS (NI, XI, UI, KNOTS, NO, XO, YO, UO, NWRK,
             WORK, IER)

like, that's the whole summoning ritual. no cap. 🦋

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🌸 DESCRIPTION 🌸

okay so here's every single argument, and I need you to actually read them because Fortran does NOT play:

• NI — (integer, input) the number of input data points. it MUST be that NI .gt. 3 and, depending on how big KNOTS is (see below), NI might have to be even bigger than that. so like, don't be stingy with your points. 💅
• XI — (real, input) an array holding the X–Y coordinates of your input data points, dimensioned for 2 x NI. XI(1,L) is the X coordinate and XI(2,L) is the Y coordinate for the input domain, for L=1,NI. two rows, bestie, that's the whole thing. ✨
• UI — (real, input) an array dimensioned for NI containing the function values at the input XI values. so UI(L) is the value of the input function at the coordinate (XI(1,L),XI(2,L)) for L=1,NI. slay. 🫶
• KNOTS — (integer, input) the number of knots used to build the approximation spline. KNOTS is dimensioned for 2 and gives you the knot count for the X direction and the Y direction. BOTH KNOTS(1) and KNOTS(2) must be at least 4. and here's the tea: the bigger your KNOTS values, the closer the approximated curve comes to actually passing through your input function values. more knots = more clingy. 👑
• NO — (integer, input) the number of coordinate values in the output list. NO can be any positive number. literally any positive one. live your life. 🌈
• XO — (real, input) an array dimensioned for NO holding the X coordinates of the output list.
• YO — (real, input) an array dimensioned for NO holding the Y coordinates of the output list.
• UO — (real, output) an array dimensioned for NO holding the calculated function values for the output spline. UO(I) is the calculated functional value at (XO(I),YO(I)) for I=1,NO. this is the one that comes back with the goods. 💖
• NWRK — (integer, input) the size of the WORK array. NWRK must be at least KNOTS(1)*KNOTS(2)*(KNOTS(1)*KNOTS(2)+3). yes that's a real formula. yes you have to compute it. no you cannot skip it. 😭
• WORK — (real, input) a work array dimensioned for NWRK.
• IER — (integer, output) the error return value. if IER comes back as 0, then no errors were detected, we love that for you. if IER is non-zero, then go refer to the man page for csagrid_errors for the details. don't ignore her. 🙈

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💅 USAGE 💅

so you call CSA2LS when you want an approximating cubic spline surface for two-dimensional input data, with the output values calculated at a list of points YOU specify. main character energy, honestly.

but listen — if you want to weight the input data values, or calculate derivatives, or handle data sparse areas specially, then babe you need CSA2LXS instead. CSA2LS is the simple entry, remember? she's the easy one. 🧚

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🔥 ACCESS 🔥

to use CSA2LS, load the NCAR Graphics library ngmath. that's the door code. 🚪✨

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🦋 SEE ALSO 🦋

• csagrid
• csa2s
• csa2xs
• csa2ls

and if you want the FULL lore, complete documentation for Csagrid lives at:

http://ngwww.ucar.edu/ngdoc/ng/ngmath/csagrid/csahome.html

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🎀 COPYRIGHT 🎀

Copyright (C) 2000
University Corporation for Atmospheric Research

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

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⭐ fr fr, that's the whole page. every flag, every dimension, every formula — untouched. the vibe is mine, the facts are hers. periodt. 💜

so anyway bestie, that's CSA2LS — straight out of the UNIX manual, dated January 1999, page CSA2LS(3NCARG), brought to you by NCAR Graphics. obsessed with her, honestly. go forth and spline. 🌸💖✨