edge_weights property for graphplot()

[kescobo]

Would like to be able to do something like this:

using MetaGraphs
using PlotRecipes

g = MetaGraph(5)

add_edge!(g, 1,2)
add_edge!(g, 1,3)
add_edge!(g, 3,4)

set_prop!(g, Edge(1,2), :weight, 2.)
set_prop!(g, Edge(1,3), :weight, 3.)
set_prop!(g, Edge(3,4), :weight, 4.)

graphplot(g, edge_weights=([get_prop(g, e, :weight) for e in edges(g)], 0.5, :BrBG))

to set different sized lines for different edges. There's a node_weights property, so why not edge_weights?

[mkborregaard]

You should in principle be able to do this with linewidth (which is a standard Plots keyword for the width of lines) but there seems to be something in the recipe that breaks it.

[mkborregaard]

It's because linewidth doesn't accept a Vector. Solutions including adding that capability to Plots (might be possible using the same logic @daschw used to implement different colors for segments); or to make each edge it's own series here in GraphPlot.

[kescobo]

@mkborregaard Can you point me to the PR for segment colors? I'll take a look and see if I can replicate.

[mkborregaard]

It was this one https://github.com/JuliaPlots/Plots.jl/pull/1110 which had to be supplemented with https://github.com/JuliaPlots/Plots.jl/pull/1142/files for GR as there were some unfortunate side effects. Not sure just replicating this will work, though.

I think implementing each edge as it's own series would work, though care must be taken not to screw up the line_z functionality. It's not an easy thing to do :-)

[kescobo]

Oh - I thought you meant that a color/line segment had been implemented for graphplot specifically... this is something else. I'll take a look and see what makes sense. Could it be that adding some separate logic for graph plots while disabling stuff like line_z makes sense?

[mkborregaard]

It might be but the philosophy of Plots is to generally mostly use the existing keywords so you don't have to learn bespoke keywords for each use.

[JackDevine]

Digging up a slightly old issue here.

The desired functionality exsists:

using MetaGraphs
using LightGraphs
using GraphRecipes
using Plots

g = MetaGraph(5)

add_edge!(g, 1,2)
add_edge!(g, 1,3)
add_edge!(g, 3,4)

set_prop!(g, Edge(1,2), :weight, 2.)
set_prop!(g, Edge(1,3), :weight, 3.)
set_prop!(g, Edge(3,4), :weight, 4.)

graphplot(g, edge_width=(s,d,w) -> get_prop(g, Edge(s,d), :weight))

Although the API is not quite the same as the one from the OP. I have wondered if it would be a good idea to let users store formatting suggestions in a MetaGraph in some sort of standard format and have graphplot parse that information and produce the right keyword arguments. In my proposed idea, the above example would become:

using MetaGraphs
using LightGraphs
using GraphRecipes
using Plots

g = MetaGraph(5)

add_edge!(g, 1,2)
add_edge!(g, 1,3)
add_edge!(g, 3,4)

set_prop!(g, Edge(1,2), :edge_width, 2.)
set_prop!(g, Edge(1,3), :edge_width, 3.)
set_prop!(g, Edge(3,4), :edge_width, 4.)

graphplot(g)