Fix bound_truncation for TaylorModel1 with TaylorN{T} coeffs (#136)

* Add method of bound_truncation for TaylorModel1 involving TaylorN{T} coeffs

* Add tests

* Bump patch version

Project.toml

@@ -1,7 +1,7 @@
 name = "TaylorModels"
 uuid = "314ce334-5f6e-57ae-acf6-00b6e903104a"
 repo = "https://github.com/JuliaIntervals/TaylorModels.jl.git"
-version = "0.5.3"
+version = "0.5.4"
 
 [deps]
 IntervalArithmetic = "d1acc4aa-44c8-5952-acd4-ba5d80a2a253"

src/auxiliary.jl

@@ -77,6 +77,17 @@ for TM in tupleTMs
     end
 end
 
+function bound_truncation(::Type{TaylorModel1}, a::Taylor1{TaylorN{T}}, aux::Interval,
+        order::Int) where {T}
+    order ≥ get_order(a) && return zero(aux)
+    # Assumes that the domain for the TaylorN variables is the symmetric normalized box -1 .. 1
+    symIbox = IntervalBox(-1 .. 1, get_numvars())
+    res = Taylor1(evaluate.(a.coeffs, Ref(symIbox)))
+    res[0:order] .= zero(res[0])
+    return res(aux)
+end
+
+
 function fixorder(a::TaylorModelN, b::TaylorModelN)
     @assert tmdata(a) == tmdata(b)
     a.pol.order == b.pol.order && return a, b

test/TM1.jl

@@ -197,6 +197,28 @@ end
         t = Taylor1([qaux,1], orderT)
         tm = TaylorModel1(deepcopy(t), -0.25 .. 0.25, x00, dom)
         @test integrate(tm, symIbox) == TaylorModel1(integrate(t), remainder(tm)*(domain(tm)-expansion_point(tm)), x00, dom)
+
+        # Changing order of a TM1 with TaylorN coeffs
+        t = Taylor1([qaux, 1], orderT)
+        tm = TaylorModel1(deepcopy(t), 0 .. 0, x00, dom)   # order 4
+        t8 = Taylor1([qaux, 1], 2*orderT)
+        tm8 = TaylorModel1(deepcopy(t8), 0 .. 0, x00, dom)
+        tm4, _ = TaylorSeries.fixorder(tm8, tm)
+        @test get_order(tm4) == get_order(tm)
+        @test polynomial(tm4) == polynomial(tm)
+        #
+        exp_tm = exp(tm)
+        exp_tm8 = exp(tm8)
+        exp_tm4, _ = TaylorSeries.fixorder(exp_tm8, tm)
+        @test get_order(exp_tm4) == get_order(exp_tm)
+        @test polynomial(exp_tm4) == polynomial(exp_tm)
+        for ind = 1:_num_tests
+            xξ = rand(dom)-x00
+            qξ = rand(symIbox)
+            tt = t(xξ)(qξ)
+            @test exp(tt) ⊆ exp_tm4(dom-x00)(symIbox)
+            @test exp(tt) ⊆ exp_tm(dom-x00)(symIbox)
+        end
     end
 
     @testset "RPAs, functions and remainders" begin