test: add tests for PiecewiseConstantFunction

Author: FedericoStra

test/runtests.jl

@@ -7,9 +7,10 @@ using TestSetExtensions
     @safetestset "Aqua tests" include("Aqua.jl")
 
     @testset "ConservationLawsParticles.jl" begin
-        @safetestset "Densities"  include("test_densities.jl")
-        @safetestset "Velocities" include("test_velocities.jl")
-        @safetestset "Utils"      include("test_utils.jl")
+        @safetestset "Densities"    include("test_densities.jl")
+        @safetestset "Velocities"   include("test_velocities.jl")
+        @safetestset "PC functions" include("test_pcf.jl")
+        @safetestset "Utils"        include("test_utils.jl")
     end
 
 end

test/test_pcf.jl

@@ -0,0 +1,35 @@
+using ConservationLawsParticles
+const PCF = PiecewiseConstantFunction
+
+@testset "map" begin
+    pcf = PCF([0., 1.], [0., 1., 2.])
+    @test map(x -> x+1, pcf) == PCF([0., 1.], [1., 2., 3.])
+end
+
+@testset "abs" begin
+    pcf = PCF([0., 1.], [-1., 0., 1.])
+    @test abs(pcf) == PCF([0., 1.], [1., 0., 1.])
+end
+
+@testset "ops" begin
+    f = PCF([   0.,    1., 2., 3.], [0., 1., 2., -1., 4.])
+    g = PCF([-1., 0.5, 1.,  2.5],   [0., 1., -1., 0., 1.])
+    @test f + g == PCF([-1., 0., 0.5, 1., 2., 2.5, 3.], [0., 1., 2., 0., 2., -1., 0., 5.])
+    @test f - g == PCF([-1., 0., 0.5, 1., 2., 2.5, 3.], [0., -1., 0., 2., 2., -1., -2., 3.])
+    @test f * g == PCF([-1., 0., 0.5, 1., 2., 2.5, 3.], [0., 0., 1., -1., 0., 0., -1., 4.])
+    f_g = f / g # cannot use == directly because f_g.values contains NaN
+    @test f_g.cuts == [-1., 0., 0.5, 1., 2., 2.5, 3.]
+    @test isnan(f_g.values[1])
+    @test f_g.values[2:end] == [0., 1., -1., Inf, -Inf, -1., 4.]
+end
+
+@testset "lpnorm" begin
+    pcf = PCF([0., 1., 11.], [0., 2., 3., 0.])
+    @test lpnorm(pcf, 1) == 2 + 30
+    @test lpnorm(pcf, 2) == sqrt(2^2 + 10*3^2)
+    @test lpnorm(pcf, Inf) == 3
+
+    pcf = PCF([0., 1.], [1., 1., 1.])
+    # @test lpnorm(pcf, 1) == Inf
+    @test lpnorm(pcf, Inf) == 1
+end