add tests, fixes to DiGraph construction

Author: Vincent Landau

src/rastergraphs.jl

@@ -29,6 +29,7 @@ end
     weightedrastergraph(
         weight_raster::GeoArray;
         directed::Bool = false,
+        condition_raster::GeoArray = weight_raster,
         condition::Function = is_data,
         cardinal_neighbors_only::Bool = false,
         connect_using_avg_raster_val::Bool = true
@@ -307,7 +308,7 @@ function make_raster_graph(
                     north_idx = CartesianIndex((row - 1, column))
 
                     # "West"
-                    if column != dims[2] && vertex_raster[west_idx] != 0 && 
+                    if column != 1 && vertex_raster[west_idx] != 0 && 
                         weight_raster[west_idx] != no_data_val
                         if condition(condition_raster[source_idx],
                                      condition_raster[west_idx])
@@ -320,7 +321,7 @@ function make_raster_graph(
                     end
 
                     # "North"
-                    if column != dims[2] && vertex_raster[north_idx] != 0 && 
+                    if row != 1 && vertex_raster[north_idx] != 0 && 
                         weight_raster[north_idx] != no_data_val
                         if condition(condition_raster[source_idx],
                                      condition_raster[north_idx])
@@ -339,7 +340,7 @@ function make_raster_graph(
                         sw_idx = CartesianIndex((row + 1, column - 1))
 
                         # "Northwest"
-                        if column != dims[2] && row != 1 && 
+                        if column != 1 && row != 1 && 
                             vertex_raster[nw_idx] != 0 && 
                             weight_raster[nw_idx] != no_data_val
                             if condition(condition_raster[source_idx],
@@ -353,7 +354,7 @@ function make_raster_graph(
                         end
 
                         # "Southwest"
-                        if row != dims[1] && column != dims[2] && 
+                        if row != dims[1] && column != 1 && 
                             vertex_raster[sw_idx] != 0  && 
                             weight_raster[sw_idx] != no_data_val
                             if condition(condition_raster[source_idx],

test/rasterdigraphs.jl

@@ -0,0 +1,70 @@
+using ArchGDAL, GeoData, LightGraphs, SimpleWeightedGraphs, SpatialGraphs
+A_array = Array{Float64}(undef, (3, 4, 1))
+A_array[:,:,:] = [1, 3, 2, 0.5, 10, 8, 5, -9999, 3, 1, 2, 6]
+
+condition_array = Array{Float64}(undef, (3, 4, 1))
+condition_array[:,:,:] = [1, 3, 5, 2, 4, 8, 5, -9999, 2, 3, 6, 7]
+
+x = X(1:4)
+y = Y(1:3)
+band = Band(1:1)
+
+weight_raster = GeoArray(A_array, (y, x, band), missingval = -9999)
+condition_raster = GeoArray(condition_array, (y, x, band), missingval = -9999)
+
+compare = <
+rasgraph = weightedrastergraph(
+    weight_raster,
+    directed = true,
+    condition_raster = condition_raster,
+    condition = compare
+)
+
+# no vertices in NoData pixels?
+@test (rasgraph.vertex_raster .== 0) == 
+        ((weight_raster .== weight_raster.missingval) .| 
+         isnan.(weight_raster))
+
+# Is the number of of vertices correct, and is the range of values correct?
+@test sort(collect(rasgraph.vertex_raster[rasgraph.vertex_raster .!= 0])) == 
+        collect(1:sum(
+            (weight_raster .!= weight_raster.missingval) .& 
+                (!).(isnan.(weight_raster))
+        ))
+
+graph_edges = collect(edges(rasgraph))
+
+# Test that the edges are correct and have proper weights
+for i in 1:length(graph_edges)
+    source_i = src(graph_edges[i])
+    dest_i = dst(graph_edges[i])
+    weight_i = graph_edges[i].weight
+
+    source_coords = findall(rasgraph.vertex_raster .== source_i)[1]
+    dest_coords = findall(rasgraph.vertex_raster .== dest_i)[1]
+
+    # Check that condition is met
+    @test compare(
+        condition_raster[source_coords],
+        condition_raster[dest_coords]
+    )
+
+    # Test that source row is within 1 step of dest row
+    row_diff = abs(source_coords[1] - dest_coords[1])
+    @test row_diff <= 1
+
+    # Test that source column is within 1 step of dest row
+    col_diff = abs(source_coords[2] - dest_coords[2])
+    @test col_diff <= 1
+
+    # Test that the weight is what it should be (assumes connect_using_avg_weights = true in graph construction)
+    if (row_diff == 1 && col_diff == 1) # get diagonal average
+        @test weight_i == 
+            SpatialGraphs.res_diagonal_avg(weight_raster[source_coords], 
+                                           weight_raster[dest_coords])
+    else
+        @test weight_i == 
+            SpatialGraphs.res_cardinal_avg(weight_raster[source_coords],
+                                           weight_raster[dest_coords])
+    end
+end

test/rastergraphs.jl

@@ -12,12 +12,12 @@ rasgraph2d = weightedrastergraph(weight_raster2d)
 rasgraph = weightedrastergraph(weight_raster)
 
 # Test that graphs are the same regardless of whether weight_raster has Band dim
-@test rasgraph2d.graph == rasgraph3d.graph
+@test rasgraph2d.graph == rasgraph.graph
 
 # no vertices in NoData pixels?
 @test (rasgraph.vertex_raster .== 0) == 
-        ((weight_raster3d .== weight_raster3d.missingval) .| 
-         isnan.(weight_raster3d))
+        ((weight_raster .== weight_raster.missingval) .| 
+         isnan.(weight_raster))
 
 # Is the number of of vertices correct, and is the range of values correct?
 @test sort(collect(rasgraph.vertex_raster[rasgraph.vertex_raster .!= 0])) == 

test/runtests.jl

@@ -1,5 +1,9 @@
 using Test, SpatialGraphs
 
-@testset "placeholder" begin
+@testset "Raster Graph Construction" begin
+    include("rastergraphs.jl")
+end
 
+@testset "Raster DiGraph Construction" begin
+    include("rasterdigraphs.jl")
 end