cryptic error when using line_plot

[Jiehong]

Hello,

I use numbat on the cli, and I saw that some plot functions now exist. So I tried to run:

let A0 = 3 cm
let ω = 20 Hz
let λ = 1.5 s

fn amplitude(t) = A0 exp(-t/λ) cos(ω t)

line_plot(amplitude, 0 s, 8 s) |>
  xlabel("Time") |>
  ylabel("Amplitude") |>
  show

I expected the show to maybe fail, but maybe I could save it to svg or something.

However, it never reached that point at all, because the following line fails with an error:

>>> line_plot(amplitude, 0 s, 8 s)
error: runtime error
 = User error: …

The ... are not something I added.

So I guess I am a user, and thus an error :D

So, perhaps functions not supported in the CLI show not be callable with an error saying this function is only supported in the browser, or (bigger fix I think), the plot function should work in the CLI, but show could be replaced by save_svg or something like that (`àla matplotlib: https://matplotlib.org/stable/api/_as_gen/matplotlib.pyplot.savefig.html).

[Goju-Ryu]

That is very likely caused by unit_of being called on a value of zero. See #521 for more context.
It required a hotfix and the error message for that is the "..." you experience.

[Goju-Ryu]

I just checked the implementation and can confirm it is because your second argument is 0. Use a value slightly higher or lower and it should be resolved.

[sharkdp]

Let's leave this open until this #521 mess is resolved 😄. Users should not have to adapt their plot ranges because of this.

[Goju-Ryu]

Yeah, I formulated myself in an unfortunate way. I meant that the error would be avoided, but this is absolutely a valid problem and one of the most common values for a starting point shouldn't trigger an error.

[sharkdp]

Closed via e8bac1f