CURV1(3NCARG)

✨ CURV1 — the set-up bestie for CURV2 ✨

okay so real quick, this is CURV1(3NCARG) from the NCAR GRAPHICS manual, and it's literally the little pre-game routine that gets everything ready for CURV2. no cap. it does set-up for CURV2. that's the whole vibe. 🎀

🌸 SYNOPSIS 🌸

CALL CURV1 (N, X, Y, SLP1, SLPN, ISLPSW, YP, TEMP, SIGMA, IER)

that's it. that's the incantation. copy it exactly, bestie, don't freestyle it 💅

💖 DESCRIPTION 💖

here's the tea on every single argument, no skips, we're going through ALL of them:

• N — (integer, input) the number of input data values you're feeding in. and like, it has to be N > 1, okay? more than one, we don't do lonely data points here 🫶
• X — (real, input) an array holding the abscissae for the input function. that's the x-coordinates, the horizontal girlies ✨
• Y — (real, input) an array with the functional values of your input data — so Y(K) is the functional value at X(K) for K=1,N. the vertical besties, matched up one-to-one, we love a paired set 😌
• SLP1 — (real, input) a value you specify for the desired slope at X(1). but like… if you'd rather have it calculated internally, go peek at ISLPSW below 👀
• SLPN — (real, input) same energy but for the end: a user-specified value for the desired slope at X(N). again, ISLPSW is your girl if you want it done internally.
• ISLPSW — (integer, input) the switch that decides whether the slopes at the end points get calculated internally. four moods, pick one:
  • = 0 if SLP1 and SLPN are user-specified.
  • = 1 if SLP1 is user-specified, but SLPN is internally calculated.
  • = 2 if SLPN is user-specified, but SLP1 is internally calculated.
  • = 3 if SLP1 and SLPN are internally calculated.

like it's giving "how much do you want me to handle for you" and honestly? valid question 🧚

• YP — (real, output) contains values for the second derivative (CURV1 computes these). so yeah, it's an output, it does the math, you just receive the gift 💝
• TEMP — (real, input) scratch space. just… space to scribble. the notes app of arguments 📝
• SIGMA — (real, input) the tension factor. and the range here is WILD:
  • values near zero result in a cubic spline
  • large values (e.g. 50) result in nearly a polygonal line
  • a typical value is 1

so like, lowkey → smooth and curvy, highkey → sharp and angular. 1 is the main character default, periodt 🔥

• IER — (integer, output) the error return value. if IER comes back as 0, then no errors were detected, slay, we're good 🎉

but if it's not zero, here's what it means:

• = 1 if N is less than 2.
• = 2 if X values are not strictly increasing.

bestie, watch that second one especially — your X values HAVE to be strictly increasing. not "mostly", not "kinda", strictly. if they're not, IER will absolutely snitch on you 💀

🔑 ACCESS 🔑

to use CURV1, you gotta load the NCAR Graphics library ngmath. that's the entry fee, no way around it ✨

👀 SEE ALSO 👀

• curv2
• fitgrid_params

complete documentation for Fitgrid is available at URL http://ngwww.ucar.edu/ngdoc/ng/ngmath/fitgrid/fithome.html — go read it, iykyk 🌈

©️ COPYRIGHT ©️

Copyright (C) 2000 University Corporation for Atmospheric Research

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

and that's the whole page, bestie 💜 this was CURV1(3NCARG) from UNIX, dated March 1998 — yeah she's an icon from the 90s and she's still serving. go forth and set up your CURV2 👑🦋💖