KURV2(3NCARG)

💖 KURV2 — it's giving interpolation, bestie 💖

okay so this is KURV2, a page from the NCAR GRAPHICS manual (section 3NCARG, if you're keeping track 🎀), and it literally does interpolation for parametric curves. no cap.

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✨ NAME ✨

KURV2 — does interpolation for parametric curves 🦋

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🌸 SYNOPSIS 🌸

CALL KURV2 (T, XS, YS, N, X, Y, XP, YP, S, SIGMA)

so here's the vibe: the interpolated curve is parameterized by mapping points in the interval [0.,1.] onto the interpolated curve. the resulting curve has a parametric representation where both of its components are splines under tension, and they're functions of the polygonal arc length. the value 0. is mapped onto (X[1],Y[1]) and the value 1. is mapped onto (X[N],Y[N]). 💫

🚨 bestie listen — KURV1 must be called before calling KURV2. not optional. don't skip it. 🙈

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💅 DESCRIPTION 💅

• T — (real, input) a value to be mapped to a point on the curve. the interval [0.,1.] is mapped onto the curve such that 0. is mapped to (X(1),Y(1)) and 1. is mapped to (X(N),Y(N)). values outside of [0.,1.] result in extrapolation 😳 so like, stay in your lane unless you're being intentional about it.
• XS — (real, output) contains the X coordinate of the interpolated point that T maps to. iconic. 💖
• YS — (real, output) contains the Y coordinate of the interpolated point that T maps to. slay. 💖
• N — (integer, input) the number of input data points. (N > 1) fr fr, it's gotta be more than one.
• X — (real, input) an array containing the X values of the input points.
• Y — (real, input) an array containing the Y values of the input points. adjacent pairs of points must be distinct — like, no duplicates, they have to actually be different points, okay? 🫶
• XP — (real, input) an array of length N as computed by KURV1.
• YP — (real, input) an array of length N as computed by KURV1.
• S — (real, input) an array of length N containing the polygonal arc lengths of the curve.
• SIGMA — (real, input) tension factor. values near zero result in a cubic spline; large values (e.g. 50) result in nearly a polygonal line. a typical value is 1. it's giving tension, literally ✨

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🌈 ACCESS 🌈

to use KURV2, load the NCAR Graphics library ngmath. that's the one. that's the whole access situation. 👑

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🦋 SEE ALSO 🦋

• kurv1
• fitgrid_params

complete documentation for Fitgrid is available at URL http://ngwww.ucar.edu/ngdoc/ng/ngmath/fitgrid/fithome.html — go read it, bestie, it's right there 📚

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👑 COPYRIGHT 👑

Copyright (C) 2000 University Corporation for Atmospheric Research

the use of this Software is governed by a License Agreement. read it, respect it, periodt. 💜

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and that's the whole page, bestie!! this one's from March 1998, it's the UNIX version of the KURV2(3NCARG) page, and honestly? she's a classic. stay interpolated, stay iconic. 💖✨🎀