[FR] How to include a contour plot in the legend?

[akriegman]

I am using a contour plot with a single level to plot an equipotential. I'd like to have a legend entry for this curve instead of the colorbar, since the colorbar isn't very useful when there's only one level. I managed to hide the color bar, but I was unable to get a legend entry to appear. MWE:

contour(
  -1:0.1:1, -1:0.1:1, (x, y) -> sin(x*y),
  levels = [0.2],
  colorbar = false,
  label = "line", # does nothing
)

Any ideas? Can this feature be added?

[BeastyBlacksmith]

Thats currently disabled. See here:

Plots.jl/src/subplots.jl

Lines 42 to 61 in 54a6518

	function should_add_to_legend(series::Series)
	series.plotattributes[:primary] &&
	series.plotattributes[:label] != "" &&
	!(
	series.plotattributes[:seriestype] in (
	:hexbin,
	:bins2d,
	:histogram2d,
	:hline,
	:vline,
	:contour,
	:contourf,
	:contour3d,
	:surface,
	:wireframe,
	:heatmap,
	:image,
	)
	)
	end

You could check out, what the side-effects are of enabling it and play with it in a PR.

As a workaround you could add an empty plot with a legend entry.

[akriegman]

I went with the empty plot trick. Thanks!

[jonniediegelman]

Can we open this back up? I'd really like to have this feature and the empty plot trick doesn't play well with plot recipes.