fixed TCI2 history bug + additional integral test

Author: rittermarc

src/tensorci2.jl

@@ -778,8 +778,8 @@ function sweep2site!(
         extraIset = tci.Iset
         extraJset = tci.Jset
         if length(tci.Iset_history) > 0
-            extraIset = union(extraIset, tci.Iset_history[end])
-            extraJset = union(extraJset, tci.Jset_history[end])
+            extraIset = union.(extraIset, tci.Iset_history[end])
+            extraJset = union.(extraJset, tci.Jset_history[end])
         end
     end
 

test/test_integration.jl

@@ -2,7 +2,7 @@ using Test
 import TensorCrossInterpolation as TCI
 import Random
 
-@testset "Integration" begin
+@testset "Integrate polynomials" begin
     Random.seed!(1234)
 
     coefficients = [
@@ -25,3 +25,12 @@ import Random
     exactval = prod(polynomialintegral.(b) .- polynomialintegral.(a))
     @test TCI.integrate(Float64, f, a, b) ≈ exactval
 end
+
+@testset "Integrate 10d function" begin
+    function f(x)
+        return 1000 * cos(10 * sum(x .^ 2)) * exp(-sum(x)^4 / 1000)
+    end
+    I15 = TCI.integrate(Float64, f, fill(-1.0, 10), fill(+1.0, 10); GKorder=15, tolerance=1e-8)
+    Iref = -5.4960415218049
+    @test abs(I15 - Iref) < 1e-3
+end