Add plot recipe for pks

[MrHenning]

Hi,
I don't know if this is desirable, but I added a plot-recipe for peaks, to be used as

using Peaks, Plots
t = 0:1/100:1
y = 2*sin.(5*t)+3*sin.(10*t)+2*sin.(30*t)
pks, vals = findmaxima(y)
pks, proms = peakproms!(pks, y; minprom=1)
plt = peaksplot(t, y, peaks=pks)
# or `peaksplot(t, y, peaks=pks, maxima=false)` to plot minima

Only RecipesBase is added as a (very lightweight) dependency, Plots.jl must be installed by the user, or will be installed when running the unit tests.

Heavily inspired by JuliaNLSolvers/LsqFit.jl#180

PS: Thanks for this great package, it has served me extensively in the past :)

[halleysfifthinc]

Thanks for the PR! I rebased on master and made some tweaks to the interface and presentation.

The tests will need to be updated but I think that is all that is needed to merge. I plan on updating the tests tomorrow unless you get to them first! 😁

[MrHenning]

Nice! 🙂
I'll try to update the test later today!

[MrHenning]

@halleysfifthinc I updated the test, but the horizontal prominence lines are broken in the plot.
So I removed the drop_irrelevant_side method, since it works better without it ^^
I updated the README.md and plots/ as well.

If you don't agree with the changes, feel free to revert them, or you can tell me what to do 🙂

[halleysfifthinc]

Any ideas how we could avoid unnecessarily duplicating series when making the extrema figure?

[halleysfifthinc]

This is why I prefer dropping the unneeded side from the prominence lines:

I'm also not a fan of the left side of the width line just floating, but I don't know what an equivalent solution would be.

[MrHenning]

ah ok I understand 😅
I'll revert the change I made

[halleysfifthinc]

One last question: I'm not familiar with the Plots ecosystem (I use PlotlyJS directly). Is a subject-verb phrasing (e.g. peaksplot) a common naming convention for recipes? I would otherwise prefer a more imperative, verb-subject phrasing (i.e. plotpeaks).

[MrHenning]

I would say it’s the more common order, seeStatsPlots.jl or GraphRecipes.jl

But I have no strong opinion on this. plotpeaks indeed sounds more intuitive if I think about it.

[halleysfifthinc]

Hmm I think a key difference compared to plots in StatsPlots or GraphRecipes is that those are well-known named kinds of plots with proper names, whereas in this case I don't think that a "peaks" plot is a distinct/common named plot format. I'll switch it to plotpeaks and merge.

FYI There are another couple of updates I have planned before tagging v0.5.0, so I won't be tagging/releasing immediately.

[MrHenning]

Ok, no hurry from my side!

Thanks for the review!!! 😀