updated developers guide + tests

test/test_randomfields.jl

@@ -0,0 +1,34 @@
+# This file is a part of JuliaFEM.
+# License is MIT: see https://github.com/JuliaFEM/JuliaFEM.jl/blob/master/LICENSE.md
+
+module RandomFieldTests
+
+using JuliaFEM
+using JuliaFEM: DiscreteField, Field, Increment, Quad4
+using JuliaFEM.Test
+
+type RandomField <: DiscreteField
+    mu :: Float64
+    std :: Float64
+end
+
+Base.first(field::RandomField) = Increment(randn(2, 4).*field.std^2 + field.mu)
+
+
+function test_interpolate_in_time()
+    r = RandomField(10.0, 0.0)
+    f = Increment(ones(2, 4)*10.0)
+    @test r(0.0) == f
+    @test r(-Inf) == f
+    @test r(+Inf) == f
+    @test r(1.0) == f
+end
+
+function test_interpolate_in_spatial_domain()
+    basis = Quad4([1, 2, 3, 4]).basis
+    r = RandomField(10.0, 0.0)
+    feval = basis(r(0.0), [0.0, 0.0])
+    @test feval == [10.0, 10.0]
+end
+
+end