Add simultaneous intervals on smooths in draw.gam()

[gavinsimpson]

Discussed in #313

^{Originally posted by AlainZuur September 6, 2024}
Hello...what would be the easiest way to get simultaneous CIs with draw()? I can get them manually with confint...but it would be much easier if draw() could plot them (I don't think it can??).

I can see how to do it manually:
https://gavinsimpson.github.io/gratia/articles/custom-plotting.html
This part:
sm <- smooth_estimates(m) |> add_confint()
And then replace by: confint and adjust the type argument. Is there any way of doing this faster?

Or change that line in draw.gam?
Alain

[louisebarbet]

Hello. I am new to the package and together with @EliotFr5 and
under the supervision of [@katossky / @JMeyer31] we are willing to solve this
issue, as part of an assignment at the ENSAI school of statistical engineering
(France). We will try to be as autonomous as possible but we may ask for guidance from now and then. We
have a solid background in statistics and a reasonable one in computer science.
If any maintainer thinks this issue is too ambitious for a beginner, please tell
us so and - if you have time - guide us to a project / issue were our help may
be more useful.