[BUG] Plots backend documentation unclear

[japhir]

Hi! New Julia learner here!

Tried to file this first with Julia, but was told to file the issue here instead JuliaLang/julia#53229.

I've just tried to reproduce this section of the manual but I get the following error:

$ JULIA_PKG_PRECOMPILE_AUTO=0 julia -e 'import Plots; Plots.set_default_backend!(:pythonJULIA_PKG_PRECOMPILE_AUTO=0 julia -e 'import Plots; Plots.set_default_backend!(:pythonplot)'plot)'
ERROR: UndefVarError: `set_default_backend!` not defined
Stacktrace:
 [1] top-level scope
   @ none:1

I found the Plots backend section a little hard to follow: I wanted to understand how to create an interactive version of a plot, which lead me to conclude that I should switch the backend.

Also, PlotlyJS supports saving the output to more formats than Plotly, such as EPS and PDF, and thus is the recommended version of Plotly for developing publication-quality figures.

made me think I should try this out, but I didn't see any docs on how to change the backend temporarily in the docs. Only the above permanent change (that didn't work).

I've also installed Preferences, since the top of the page mentions that this mechanism is used. Still no luck though.
I've now installed PlotlyJS explicitly, but I still get the same error.

I hope this is a helpful issue!

Versions

Plots.jl version: [91a5bcdd] Plots v1.40.1
Backend version (]st -m <backend(s)>): [f0f68f2c] PlotlyJS v0.18.12
Output of versioninfo():

Julia Version 1.10.0
Commit 3120989f39 (2023-12-25 18:01 UTC)
Build Info:

    Note: This is an unofficial build, please report bugs to the project
    responsible for this build and not to the Julia project unless you can
    reproduce the issue using official builds available at https://julialang.org/downloads

Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
  CPU: 4 × Intel(R) Core(TM) i7-7500U CPU @ 2.70GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-15.0.7 (ORCJIT, skylake)
  Threads: 1 on 4 virtual cores

I've installed julia through the pacman package manager for Arch Linux.

[BeastyBlacksmith]

Yeah, the docs need to be updated to reflect #4870 .
To temporarily use a different backend you just call the backend function like using Plots; pythonplot(). If it is only for a specific block you can also use with:

with(:pythonplot) do
    plot(1:5)
end