added dispatch for color graph

Author: pkj-m

src/coloring/greedy_star1_coloring.jl

@@ -21,7 +21,7 @@
 
     Reference: Gebremedhin AH, Manne F, Pothen A. **What color is your Jacobian? Graph coloring for computing derivatives.** SIAM review. 2005;47(4):629-705.
 """
-function greedy_star1_coloring(g::LightGraphs.AbstractGraph)
+function color_graph(g::LightGraphs.AbstractGraph, ::GreedyStar1Color)
     v = nv(g)
     color = zeros(Int64, v)
 

src/coloring/greedy_star2_coloring.jl

@@ -24,7 +24,7 @@
     TODO: add text explaining the difference between star1 and
     star2
 """
-function greedy_star2_coloring(g::LightGraphs.AbstractGraph)
+function color_graph(g::LightGraphs.AbstractGraph, :: GreedyStar2Color)
     v = nv(g)
     color = zeros(Int64, v)
 

src/coloring/high_level.jl

@@ -2,6 +2,8 @@ abstract type ColoringAlgorithm end
 struct GreedyD1Color <: ColoringAlgorithm end
 struct BSCColor <: ColoringAlgorithm end
 struct ContractionColor <: ColoringAlgorithm end
+struct GreedyStar1Color <: ColoringAlgorithm end
+struct GreedyStar2Color <: ColoringAlgorithm end
 
 """
     matrix_colors(A,alg::ColoringAlgorithm = GreedyD1Color())

test/test_greedy_star.jl

@@ -37,8 +37,8 @@ colors.
 for i in 1:5
     g = test_graphs[i]
 
-    out_colors1 = SparseDiffTools.greedy_star1_coloring(g)
-    out_colors2 = SparseDiffTools.greedy_star2_coloring(g)
+    out_colors1 = SparseDiffTools.color_graph(g,SparseDiffTools.GreedyStar1Color())
+    out_colors2 = SparseDiffTools.color_graph(g,SparseDiffTools.GreedyStar2Color())
 
     #test condition 1
     for v = vertices(g)