Move Plots as a weak dependence

Project.toml

@@ -8,8 +8,13 @@ Clustering = "aaaa29a8-35af-508c-8bc3-b662a17a0fe5"
 Distributions = "31c24e10-a181-5473-b8eb-7969acd0382f"
 KrylovKit = "0b1a1467-8014-51b9-945f-bf0ae24f4b77"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
+
+[weakdeps]
 Plots = "91a5bcdd-55d7-5caf-9e0b-520d859cae80"
 
+[extensions]
+MeanFieldGraphPlotsExt = "Plots"
+
 [compat]
 Clustering = "0.15.7"
 Distributions = "0.25"

ext/MeanFieldGraphPlotsExt.jl

@@ -0,0 +1,19 @@
+module MeanFieldGraphPlotsExt
+
+using MeanFieldGraph
+using Plots: heatmap, palette
+import MeanFieldGraph: plot
+
+function plot(data::MeanFieldGraph.DiscreteTimeData)
+    N, T = size(data)
+    return heatmap(
+        data.X;
+        color=palette(:binary),
+        xticks=floor.(Int, range(1, T, 10)),
+        yticks=floor.(Int, range(1, N, 10)),
+        colorbar=:false,
+        tick_direction=:none,
+    )
+end
+
+end

src/MeanFieldGraph.jl

@@ -3,7 +3,6 @@ module MeanFieldGraph
 using Clustering: Clustering, ClusteringResult, assignments, counts, kmeans, hclust, cutree
 using Distributions: Distributions, Bernoulli, DiscreteUniform, fit, mean
 using LinearAlgebra: LinearAlgebra, I, transpose
-using Plots: Plots, heatmap, palette, plot
 using KrylovKit: KrylovKit, svdsolve
 
 export MarkovChainModel, DiscreteTimeData, MarkovChainConnectivity

src/plots.jl

@@ -1,18 +1,11 @@
-import Plots.plot
-
 """
     plot(data::DiscreteTimeData)
 
-Plot a black and white image corresponding to `data`. Black pixels correspond to the value `1`. The x-axis correspond to time and y-axis correspond to components.
+Plot a black and white image corresponding to `data`. Black pixels correspond to
+the value `1`. The x-axis corresponds to time and y-axis corresponds to
+components.
+
+The concrete plotting implementation is provided by a package extension when
+`Plots` is available.
 """
-function plot(data::DiscreteTimeData)
-    N, T = size(data)
-    return heatmap(
-        data.X;
-        color=palette(:binary),
-        xticks=floor.(Int, range(1, T, 10)),
-        yticks=floor.(Int, range(1, N, 10)),
-        colorbar=:false,
-        tick_direction=:none,
-    )
-end
+function plot end

test/Project.toml

@@ -5,13 +5,15 @@ Distributions = "31c24e10-a181-5473-b8eb-7969acd0382f"
 Documenter = "e30172f5-a6a5-5a46-863b-614d45cd2de4"
 JET = "c3a54625-cd67-489e-a8e7-0a5a0ff4e31b"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
+Plots = "91a5bcdd-55d7-5caf-9e0b-520d859cae80"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [compat]
 Clustering = "0.15"
 Distributions = "0.25"
 LinearAlgebra = "1"
+Plots = "1"
 Random = "1"
 Test = "1"
 julia = "1.6"

test/plots.jl

@@ -0,0 +1,10 @@
+@testset "Plot extension" begin
+    try
+        using Plots
+        data = MF.DiscreteTimeData(trues(4, 6))
+        fig = MF.plot(data)
+        @test fig !== nothing
+    catch e
+        @test_skip "Plots is not installed in active environment"
+    end
+end

test/runtests.jl

@@ -26,4 +26,5 @@ using Test
     include("simulate.jl")
     include("estimation.jl")
     include("classification.jl")
+    include("plots.jl")
 end