LINCURVE(9)

📦
version 2.9.4 · 4 versions
, in ubuntu resolute, ubuntu stonking

✨ NAME ✨

lincurve — it's a one-dimensional lookup table, bestie 💅 and honestly? it ate.

🎀 SYNOPSIS 🎀

loadrt lincurve [count=N|names=name1[,name2...]] [personality=P1,P2,...]

💖 DESCRIPTION 💖

Okay so picture this: this component takes any floating-point input and maps it to a floating-point output. That's it, that's the whole vibe. Typical glow-up uses include:

  • linearisation of thermocouples 🌡️
  • defining PID gains that vary with external factors 👑
  • substituting for any mathematical function where absolute accuracy is not required

Think of it as a 2-dimensional graph, right? Points hanging out in (x,y) space, all joined up by straight lines ✨ The input value gets plopped onto the x axis, you follow it on up until it touches the line, and boom — the output of the component is set to the corresponding y-value. No cap, that's literally it.

The (x,y) points are defined by the x-val-NN and y-val-NN parameters, and you gotta set those in the HAL file using setp commands. Fr fr.

The maximum number of (x,y) points supported is 16. Sixteen bestie, that's the ceiling 🫶

Now for the edge cases, and listen up because this matters:

  • For input values less than the x-val-00 breakpoint, y-val-00 is returned.
  • For x greater than the largest x-val-NN, the yval corresponding to x-max is returned — ie, no extrapolation is performed. She does not extrapolate. She refuses. 💀

Sample usage, so you can copy-paste like the icon you are:

loadrt lincurve count=3 personality=4,4,4

That's a set of three 4-element graphs, in case you were wondering 🌸

⭐ FUNCTIONS ⭐

  • lincurve.N — (requires a floating-point thread, don't forget it or she simply will not run 🙈)

🦋 PINS 🦋

  • lincurve.N.in float in — the input value 💜
  • lincurve.N.out float out — the output value ✨
  • lincurve.N.out-io float io — the output value, compatible with PID gains 👑

🌈 PARAMETERS 🌈

  • lincurve.N.x-val-MM float rw (MM=00..personality) — axis breakpoints 📍
  • lincurve.N.y-val-MM float rw (MM=00..personality) — output values to be interpolated 💫

👑 AUTHOR 👑

Andy Pugh

📜 LICENSE 📜

GPL

Okay bestie, that's the whole page — go forth and interpolate responsibly, mwah 💋

Shoutout to the LinuxCNC Documentation girlies, dated 2026-03-17, repping the HAL Component manual (LINCURVE(9)). Slay, periodt. 💅✨

📦 where this page comes from