methods tells you, but only if you already using the package which defines it:
julia> using Plots
julia> using StatsPlots
julia> methods(scatter)
# 1 method for generic function "scatter":
[1] scatter(args...; kw...) in Plots at C:\Users\oheil\.julia\packages\RecipesBase\92zOw\src\RecipesBase.jl:403
If you search for a function without knowing anything about it Julia can’t help in general.
First check is always ? in the REPL:
help?> scatter
search: scatter scatter! scatter3d scatter3d! scatterhist scatterhist! marginalscatter marginalscatter! AbstractPattern
scatter(x,y)
scatter!(x,y)
Make a scatter plot of y vs x.
Examples
≡≡≡≡≡≡≡≡≡≡
julia> scatter([1,2,3],[4,5,6],markersize=[3,4,5],markercolor=[:red,:green,:blue])
julia> scatter([(1,4),(2,5),(3,6)])
Second check the documentation, if available, in this case Home · Plots
Third and Fourth, depending on your preferences:
Ask here or check the source code.
As said above using ? in the REPL (but it needs to be loaded with using)
I think you are right. The Vignette system (at least for the bioconductor project) is quite standardized and nearly always at hand. But it isn’t therefore better. It’s more like: lets have the lowest possible requirement as a standard
In R if you just have a function name and nothing else you are lost like in Julia or in every other language where a package ecosystem exists.
With some exceptions I find the documentation of Julia and many packages outstanding, despite that you have to search for it and several presentations exist.
A last hint: asking here is always beneficial and perhaps the fastest way to good results, but, of course, you need to ask in a minimal specific way 