make self-loop edges curved (included in PR #186)

README.md

@@ -160,6 +160,10 @@ gplot(h)
 
 # Keyword Arguments
 + `layout` Layout algorithm: `random_layout`, `circular_layout`, `spring_layout`, `shell_layout`, `stressmajorize_layout`, `spectral_layout`. Default: `spring_layout`
++ `title` Plot title. Default: `""`
++ `title_color` Plot title color. Default: `colorant"black"`
++ `title_size` Plot title size. Default: `4.0`
++ `font_family` Font family for all text. Default: `"Helvetica"`
 + `NODESIZE` Max size for the nodes. Default: `3.0/sqrt(N)`
 + `nodesize` Relative size for the nodes, can be a Vector. Default: `1.0`
 + `nodelabel` Labels for the vertices, a Vector or nothing. Default: `nothing`

src/GraphPlot.jl

@@ -2,6 +2,8 @@ module GraphPlot
 
 using Compose  # for plotting features
 using Graphs
+using LinearAlgebra
+using SparseArrays
 
 const gadflyjs = joinpath(dirname(Base.source_path()), "gadfly.js")
 

src/layout.jl

@@ -102,11 +102,11 @@ julia> locs_x, locs_y = spring_layout(g)
 ```
 """
 function spring_layout(g::AbstractGraph,
-                       locs_x=2*rand(nv(g)).-1.0,
-                       locs_y=2*rand(nv(g)).-1.0;
+                       locs_x::Vector{R1}=2*rand(nv(g)).-1.0,
+                       locs_y::Vector{R2}=2*rand(nv(g)).-1.0;
                        C=2.0,
                        MAXITER=100,
-                       INITTEMP=2.0)
+                       INITTEMP=2.0) where {R1 <: Real, R2 <: Real}
 
     nvg = nv(g)
     adj_matrix = adjacency_matrix(g)
@@ -174,7 +174,7 @@ end
 
 using Random: MersenneTwister
 
-function spring_layout(g::AbstractGraph, seed::Integer, kws...)
+function spring_layout(g::AbstractGraph, seed::Integer; kws...)
     rng = MersenneTwister(seed)
     spring_layout(g, 2 .* rand(rng, nv(g)) .- 1.0, 2 .* rand(rng,nv(g)) .- 1.0; kws...)
 end
@@ -205,20 +205,20 @@ function shell_layout(g, nlist::Union{Nothing, Vector{Vector{Int}}} = nothing)
     if nv(g) == 1
         return [0.0], [0.0]
     end
-    if nlist == nothing
+    if isnothing(nlist)
         nlist = [collect(1:nv(g))]
     end
     radius = 0.0
     if length(nlist[1]) > 1
         radius = 1.0
     end
-    locs_x = Float64[]
-    locs_y = Float64[]
+    locs_x = zeros(nv(g))
+    locs_y = zeros(nv(g))
     for nodes in nlist
         # Discard the extra angle since it matches 0 radians.
         θ = range(0, stop=2pi, length=length(nodes)+1)[1:end-1]
-        append!(locs_x, radius*cos.(θ))
-        append!(locs_y, radius*sin.(θ))
+        locs_x[nodes] = radius*cos.(θ)
+        locs_y[nodes] = radius*sin.(θ)
         radius += 1.0
     end
     return locs_x, locs_y

src/lines.jl

@@ -201,3 +201,49 @@ function curveedge(x1, y1, x2, y2, θ, outangle, d; k=0.5)
 
     return [(x1,y1) (xc1, yc1) (xc2, yc2) (x2, y2)]
 end
+
+function build_curved_edges(g, locs_x, locs_y, nodesize, arrowlengthfrac, arrowangleoffset, outangle)
+    if arrowlengthfrac > 0.0
+        curves_cord, arrows_cord = graphcurve(g, locs_x, locs_y, nodesize, arrowlengthfrac, arrowangleoffset, outangle)
+        curves = curve(curves_cord[:,1], curves_cord[:,2], curves_cord[:,3], curves_cord[:,4])
+        carrows = line(arrows_cord)
+    else
+        curves_cord = graphcurve(g, locs_x, locs_y, nodesize, outangle)
+        curves = curve(curves_cord[:,1], curves_cord[:,2], curves_cord[:,3], curves_cord[:,4])
+        carrows = nothing
+    end
+
+    return curves, carrows
+end
+
+function build_straight_edges(g, locs_x, locs_y, nodesize, arrowlengthfrac, arrowangleoffset)
+    if arrowlengthfrac > 0.0
+        lines_cord, arrows_cord = graphline(g, locs_x, locs_y, nodesize, arrowlengthfrac, arrowangleoffset)
+        lines = line(lines_cord)
+        larrows = line(arrows_cord)
+    else
+        lines_cord = graphline(g, locs_x, locs_y, nodesize)
+        lines = line(lines_cord)
+        larrows = nothing
+    end
+
+    return lines, larrows
+end
+
+function build_straight_curved_edges(g, locs_x, locs_y, nodesize, arrowlengthfrac, arrowangleoffset, outangle)
+    A = adjacency_matrix(g) #adjacency matrix
+    B = spdiagm(diag(A)) #diagonal matrix (self-loops)
+    A[diagind(A)] .= 0 #set diagonal elements to 0 (remove self-loops)
+    if is_directed(g)
+        g1 = SimpleDiGraph(A)
+        g2 = SimpleDiGraph(B)
+    else
+        g1 = SimpleGraph(A)
+        g2 = SimpleGraph(B)
+    end
+
+    lines, larrows = build_straight_edges(g1, locs_x, locs_y, nodesize, arrowlengthfrac, arrowangleoffset)
+    curves, carrows = build_curved_edges(g2, locs_x, locs_y, nodesize, arrowlengthfrac, arrowangleoffset, outangle)
+
+    return lines, larrows, curves, carrows
+end

src/plot.jl

@@ -23,6 +23,18 @@ Layout algorithm. Currently can be one of [`random_layout`,
 `spectral_layout`].
 Default: `spring_layout`
 
+`title`
+Plot title. Default: `""`
+
+`title_color`
+Plot title color. Default: `colorant"black"`
+
+`title_size`
+Plot title size. Default: `4.0`
+
+`font_family`
+Font family for all text. Default: `"Helvetica"`
+
 `NODESIZE`
 Max size for the nodes. Default: `3.0/sqrt(N)`
 
@@ -97,6 +109,10 @@ Default: `π/5 (36 degrees)`
 """
 function gplot(g::AbstractGraph{T},
     locs_x_in::Vector{R1}, locs_y_in::Vector{R2};
+    title = "",
+    title_color = colorant"black",
+    title_size = 4.0,
+    font_family = "Helvetica",
     nodelabel = nothing,
     nodelabelc = colorant"black",
     nodelabelsize = 1.0,
@@ -206,33 +222,26 @@ function gplot(g::AbstractGraph{T},
     end
 
     # Create lines and arrow heads
-    lines, arrows = nothing, nothing
+    lines, larrows = nothing, nothing
+    curves, carrows = nothing, nothing
     if linetype == "curve"
-        if arrowlengthfrac > 0.0
-            curves_cord, arrows_cord = graphcurve(g, locs_x, locs_y, nodesize, arrowlengthfrac, arrowangleoffset, outangle)
-            lines = curve(curves_cord[:,1], curves_cord[:,2], curves_cord[:,3], curves_cord[:,4])
-            arrows = line(arrows_cord)
-        else
-            curves_cord = graphcurve(g, locs_x, locs_y, nodesize, outangle)
-            lines = curve(curves_cord[:,1], curves_cord[:,2], curves_cord[:,3], curves_cord[:,4])
-        end
+        curves, carrows = build_curved_edges(g, locs_x, locs_y, nodesize, arrowlengthfrac, arrowangleoffset, outangle)
+    elseif has_self_loops(g)
+        lines, larrows, curves, carrows = build_straight_curved_edges(g, locs_x, locs_y, nodesize, arrowlengthfrac, arrowangleoffset, outangle)
     else
-        if arrowlengthfrac > 0.0
-            lines_cord, arrows_cord = graphline(g, locs_x, locs_y, nodesize, arrowlengthfrac, arrowangleoffset)
-            lines = line(lines_cord)
-            arrows = line(arrows_cord)
-        else
-            lines_cord = graphline(g, locs_x, locs_y, nodesize)
-            lines = line(lines_cord)
-        end
+        lines, larrows = build_straight_edges(g, locs_x, locs_y, nodesize, arrowlengthfrac, arrowangleoffset)
     end
 
-    compose(context(units=UnitBox(-1.2, -1.2, +2.4, +2.4)),
-            compose(context(), texts, fill(nodelabelc), stroke(nothing), fontsize(nodelabelsize)),
+    title_offset = isempty(title) ? 0 : 0.1*title_size/4
+    compose(context(units=UnitBox(-1.2, -1.2 - title_offset, +2.4, +2.4 + title_offset)),
+            compose(context(), text(0, -1.2 - title_offset/2, title, hcenter, vcenter), fill(title_color), fontsize(title_size), font(font_family)),
+            compose(context(), texts, fill(nodelabelc), fontsize(nodelabelsize), font(font_family)),
             compose(context(), nodes, fill(nodefillc), stroke(nodestrokec), linewidth(nodestrokelw)),
             compose(context(), edgetexts, fill(edgelabelc), stroke(nothing), fontsize(edgelabelsize)),
-            compose(context(), arrows, stroke(edgestrokec), linewidth(edgelinewidth)),
-            compose(context(), lines, stroke(edgestrokec), fill(nothing), linewidth(edgelinewidth)))
+            compose(context(), larrows, stroke(edgestrokec), linewidth(edgelinewidth)),
+            compose(context(), carrows, stroke(edgestrokec), linewidth(edgelinewidth)),
+            compose(context(), lines, stroke(edgestrokec), fill(nothing), linewidth(edgelinewidth)),
+            compose(context(), curves, stroke(edgestrokec), fill(nothing), linewidth(edgelinewidth)))
 end
 
 function gplot(g; layout::Function=spring_layout, keyargs...)