Comments adressed

docs/src/extrapolation_methods.md

@@ -13,7 +13,7 @@ A = QuadraticSpline(u, t)
 plot(A)
 ```
 
-Extrapolation behavior can be set left and right of the data simultaneously with the `extension` keyword, or left and right separately with the `extension_left` and `extension_right` keywords respectively.
+Extrapolation behavior can be set left and right of the data simultaneously with the `extension` keyword, or left and right separately with the `extrapolation_left` and `extrapolation_right` keywords respectively.
 
 ## `ExtrapolationType.none`
 
@@ -51,3 +51,15 @@ plot(A)
 plot!(t_eval_down, A.(t_eval_down); label = "extrapolation down")
 plot!(t_eval_up, A.(t_eval_up); label = "extrapolation up")
 ```
+
+## Mixed extrapolation
+
+You can also have different extrapolation types left and right of the data.
+
+```@example tutorial
+A = QuadraticSpline(u, t; extrapolation_left = ExtrapolationType.constant,
+    extrapolation_right = ExtrapolationType.linear)
+plot(A)
+plot!(t_eval_down, A.(t_eval_down); label = "extrapolation down")
+plot!(t_eval_up, A.(t_eval_up); label = "extrapolation up")
+```

src/DataInterpolations.jl

@@ -64,16 +64,16 @@ function Base.showerror(io::IO, ::ExtrapolationError)
     print(io, EXTRAPOLATION_ERROR)
 end
 
-const DOWN_EXTRAPOLATION_ERROR = "Cannot extrapolate down as `extrapolation_left` keyword passed was `none`"
-struct DownExtrapolationError <: Exception end
-function Base.showerror(io::IO, ::DownExtrapolationError)
-    print(io, DOWN_EXTRAPOLATION_ERROR)
+const LEFT_EXTRAPOLATION_ERROR = "Cannot extrapolate for t < first(A.t) as the `extrapolation_left` kwarg passed was `ExtrapolationType.none`"
+struct LeftExtrapolationError <: Exception end
+function Base.showerror(io::IO, ::LeftExtrapolationError)
+    print(io, LEFT_EXTRAPOLATION_ERROR)
 end
 
-const UP_EXTRAPOLATION_ERROR = "Cannot extrapolate up as `extrapolation_right` keyword passed was `none`"
-struct UpExtrapolationError <: Exception end
-function Base.showerror(io::IO, ::UpExtrapolationError)
-    print(io, UP_EXTRAPOLATION_ERROR)
+const RIGHT_EXTRAPOLATION_ERROR = "Cannot extrapolate for t > last(A.t) as the `extrapolation_tight` kwarg passed was `ExtrapolationType.none`"
+struct RightExtrapolationError <: Exception end
+function Base.showerror(io::IO, ::RightExtrapolationError)
+    print(io, RIGHT_EXTRAPOLATION_ERROR)
 end
 
 const INTEGRAL_NOT_FOUND_ERROR = "Cannot integrate it analytically. Please use Numerical Integration methods."

src/derivatives.jl

@@ -17,7 +17,7 @@ function _extrapolate_derivative_down(A, t, order)
     (; extrapolation_left) = A
     typed_zero = zero(first(A.u) / one(A.t[1]))
     if extrapolation_left == ExtrapolationType.none
-        throw(DownExtrapolationError())
+        throw(LeftExtrapolationError())
     elseif extrapolation_left == ExtrapolationType.constant
         typed_zero
     elseif extrapolation_left == ExtrapolationType.linear
@@ -36,7 +36,7 @@ function _extrapolate_derivative_up(A, t, order)
     (; extrapolation_right) = A
     typed_zero = zero(first(A.u) / one(A.t[1]))
     if extrapolation_right == ExtrapolationType.none
-        throw(UpExtrapolationError())
+        throw(RightExtrapolationError())
     elseif extrapolation_right == ExtrapolationType.constant
         typed_zero
     elseif extrapolation_right == ExtrapolationType.linear

src/integrals.jl

@@ -65,7 +65,7 @@ end
 function _extrapolate_integral_down(A, t)
     (; extrapolation_left) = A
     if extrapolation_left == ExtrapolationType.none
-        throw(DownExtrapolationError())
+        throw(LeftExtrapolationError())
     elseif extrapolation_left == ExtrapolationType.constant
         first(A.u) * (first(A.t) - t)
     elseif extrapolation_left == ExtrapolationType.linear
@@ -80,7 +80,7 @@ end
 function _extrapolate_integral_up(A, t)
     (; extrapolation_right) = A
     if extrapolation_right == ExtrapolationType.none
-        throw(UpExtrapolationError())
+        throw(RightExtrapolationError())
     elseif extrapolation_right == ExtrapolationType.constant
         last(A.u) * (t - last(A.t))
     elseif extrapolation_right == ExtrapolationType.linear

src/interpolation_methods.jl

@@ -11,7 +11,7 @@ end
 function _extrapolate_down(A, t)
     (; extrapolation_left) = A
     if extrapolation_left == ExtrapolationType.none
-        throw(DownExtrapolationError())
+        throw(LeftExtrapolationError())
     elseif extrapolation_left == ExtrapolationType.constant
         slope = derivative(A, first(A.t))
         first(A.u) + slope * zero(t)
@@ -27,7 +27,7 @@ end
 function _extrapolate_up(A, t)
     (; extrapolation_right) = A
     if extrapolation_right == ExtrapolationType.none
-        throw(UpExtrapolationError())
+        throw(RightExtrapolationError())
     elseif extrapolation_right == ExtrapolationType.constant
         slope = derivative(A, last(A.t))
         last(A.u) + slope * zero(t)

test/derivative_tests.jl

@@ -76,8 +76,9 @@ function test_derivatives(method; args = [], kwargs = [], name::String)
         @test_throws DataInterpolations.ExtrapolationError derivative(func, t[1] - 1.0)
         @test_throws DataInterpolations.ExtrapolationError derivative(func, t[end] + 1.0)
     else
-        @test_throws DataInterpolations.DownExtrapolationError derivative(func, t[1] - 1.0)
-        @test_throws DataInterpolations.UpExtrapolationError derivative(func, t[end] + 1.0)
+        @test_throws DataInterpolations.LeftExtrapolationError derivative(func, t[1] - 1.0)
+        @test_throws DataInterpolations.RightExtrapolationError derivative(
+            func, t[end] + 1.0)
     end
     @test_throws DataInterpolations.DerivativeNotFoundError derivative(
         func, t[1], 3)

test/extrapolation_tests.jl

@@ -5,8 +5,8 @@ function test_extrapolation_errors(method, u, t)
     @test A.extrapolation_right == ExtrapolationType.none
     @test A.extrapolation_left == ExtrapolationType.none
     for (error_type, t_eval) in zip(
-        (DataInterpolations.DownExtrapolationError,
-            DataInterpolations.UpExtrapolationError),
+        (DataInterpolations.LeftExtrapolationError,
+            DataInterpolations.RightExtrapolationError),
         (first(t) - 1, last(t) + 1))
         @test_throws error_type A(t_eval)
         @test_throws error_type DataInterpolations.derivative(

test/integral_tests.jl

@@ -49,10 +49,11 @@ function test_integral(method; args = [], kwargs = [], name::String)
         @test isapprox(qint, aint, atol = 1e-6, rtol = 1e-8)
     end
     func = method(args...; kwargs...)
-    @test_throws DataInterpolations.DownExtrapolationError integral(func, t[1] - 1.0)
-    @test_throws DataInterpolations.UpExtrapolationError integral(func, t[end] + 1.0)
-    @test_throws DataInterpolations.DownExtrapolationError integral(func, t[1] - 1.0, t[2])
-    @test_throws DataInterpolations.UpExtrapolationError integral(func, t[1], t[end] + 1.0)
+    @test_throws DataInterpolations.LeftExtrapolationError integral(func, t[1] - 1.0)
+    @test_throws DataInterpolations.RightExtrapolationError integral(func, t[end] + 1.0)
+    @test_throws DataInterpolations.LeftExtrapolationError integral(func, t[1] - 1.0, t[2])
+    @test_throws DataInterpolations.RightExtrapolationError integral(
+        func, t[1], t[end] + 1.0)
 end
 
 @testset "LinearInterpolation" begin

test/interpolation_tests.jl

@@ -176,9 +176,9 @@ end
     @test A(-1.0) == -2.0
     @test A(11.0) == 22.0
     A = LinearInterpolation(u, t)
-    @test_throws DataInterpolations.DownExtrapolationError A(-1.0)
-    @test_throws DataInterpolations.UpExtrapolationError A(11.0)
-    @test_throws DataInterpolations.DownExtrapolationError A([-1.0, 11.0])
+    @test_throws DataInterpolations.LeftExtrapolationError A(-1.0)
+    @test_throws DataInterpolations.RightExtrapolationError A(11.0)
+    @test_throws DataInterpolations.LeftExtrapolationError A([-1.0, 11.0])
 end
 
 @testset "Quadratic Interpolation" begin
@@ -275,8 +275,8 @@ end
     @test A(0.0) == -4.5
     @test A(5.0) == -7.5
     A = QuadraticInterpolation(u, t)
-    @test_throws DataInterpolations.DownExtrapolationError A(0.0)
-    @test_throws DataInterpolations.UpExtrapolationError A(5.0)
+    @test_throws DataInterpolations.LeftExtrapolationError A(0.0)
+    @test_throws DataInterpolations.RightExtrapolationError A(5.0)
 end
 
 @testset "Lagrange Interpolation" begin
@@ -335,8 +335,8 @@ end
     @test A(0.0) == 0.0
     @test A(4.0) == 16.0
     A = LagrangeInterpolation(u, t)
-    @test_throws DataInterpolations.DownExtrapolationError A(-1.0)
-    @test_throws DataInterpolations.UpExtrapolationError A(4.0)
+    @test_throws DataInterpolations.LeftExtrapolationError A(-1.0)
+    @test_throws DataInterpolations.RightExtrapolationError A(4.0)
 end
 
 @testset "Akima Interpolation" begin
@@ -366,8 +366,8 @@ end
     @test A(-1.0) ≈ -5.0
     @test A(11.0) ≈ -3.924742268041234
     A = AkimaInterpolation(u, t)
-    @test_throws DataInterpolations.DownExtrapolationError A(-1.0)
-    @test_throws DataInterpolations.UpExtrapolationError A(11.0)
+    @test_throws DataInterpolations.LeftExtrapolationError A(-1.0)
+    @test_throws DataInterpolations.RightExtrapolationError A(11.0)
 end
 
 @testset "ConstantInterpolation" begin
@@ -496,8 +496,8 @@ end
     @test A(-1.0) == 1.0
     @test A(11.0) == 1.0
     A = ConstantInterpolation(u, t)
-    @test_throws DataInterpolations.DownExtrapolationError A(-1.0)
-    @test_throws DataInterpolations.UpExtrapolationError A(11.0)
+    @test_throws DataInterpolations.LeftExtrapolationError A(-1.0)
+    @test_throws DataInterpolations.RightExtrapolationError A(11.0)
 
     # Test extrapolation with infs with regularly spaced t
     u = [1.67e7, 1.6867e7, 1.7034e7, 1.7201e7, 1.7368e7]
@@ -549,8 +549,8 @@ end
     @test A(-2.0) == 0.0
     @test A(2.0) == 6.0
     A = QuadraticSpline(u, t)
-    @test_throws DataInterpolations.DownExtrapolationError A(-2.0)
-    @test_throws DataInterpolations.UpExtrapolationError A(2.0)
+    @test_throws DataInterpolations.LeftExtrapolationError A(-2.0)
+    @test_throws DataInterpolations.RightExtrapolationError A(2.0)
 end
 
 @testset "CubicSpline Interpolation" begin
@@ -602,8 +602,8 @@ end
     @test A(-2.0) ≈ -1.0
     @test A(2.0) ≈ 5.0
     A = CubicSpline(u, t)
-    @test_throws DataInterpolations.DownExtrapolationError A(-2.0)
-    @test_throws DataInterpolations.UpExtrapolationError A(2.0)
+    @test_throws DataInterpolations.LeftExtrapolationError A(-2.0)
+    @test_throws DataInterpolations.RightExtrapolationError A(2.0)
 
     @testset "AbstractMatrix" begin
         t = 0.1:0.1:1.0
@@ -647,8 +647,8 @@ end
         @test A(-1.0) == u[1]
         @test A(300.0) == u[end]
         A = BSplineInterpolation(u, t, 2, :Uniform, :Uniform)
-        @test_throws DataInterpolations.DownExtrapolationError A(-1.0)
-        @test_throws DataInterpolations.UpExtrapolationError A(300.0)
+        @test_throws DataInterpolations.LeftExtrapolationError A(-1.0)
+        @test_throws DataInterpolations.RightExtrapolationError A(300.0)
 
         A = BSplineInterpolation(u, t, 2, :ArcLen, :Average)
 
@@ -668,8 +668,8 @@ end
         @test A(-1.0) == u[1]
         @test A(300.0) == u[end]
         A = BSplineInterpolation(u, t, 2, :ArcLen, :Average)
-        @test_throws DataInterpolations.DownExtrapolationError A(-1.0)
-        @test_throws DataInterpolations.UpExtrapolationError A(300.0)
+        @test_throws DataInterpolations.LeftExtrapolationError A(-1.0)
+        @test_throws DataInterpolations.RightExtrapolationError A(300.0)
 
         @testset "AbstractMatrix" begin
             t = 0.1:0.1:1.0
@@ -726,8 +726,8 @@ end
         @test A(-1.0) == u[1]
         @test A(300.0) == u[end]
         A = BSplineApprox(u, t, 2, 4, :Uniform, :Uniform)
-        @test_throws DataInterpolations.DownExtrapolationError A(-1.0)
-        @test_throws DataInterpolations.UpExtrapolationError A(300.0)
+        @test_throws DataInterpolations.LeftExtrapolationError A(-1.0)
+        @test_throws DataInterpolations.RightExtrapolationError A(300.0)
 
         @testset "AbstractMatrix" begin
             t = 0.1:0.1:1.0

test/regularization.jl

@@ -184,7 +184,7 @@ end
         uₒ, tₒ; alg = :fixed, extrapolation_right = ExtrapolationType.extension)
     @test A(10.0) == A.Aitp(10.0)
     A = RegularizationSmooth(uₒ, tₒ; alg = :fixed)
-    @test_throws DataInterpolations.UpExtrapolationError A(10.0)
+    @test_throws DataInterpolations.RightExtrapolationError A(10.0)
 end
 
 @testset "Type inference" begin