Deprecate gausschebyshev and add gausschebyshevt, ..., `gausscheb…

…yshevw` (#123) * deprecate gausschebyshev and add gausschebyshev1 to gausschebyshev4 * fix docs * fix error handling for gausschebyshev * update docstrings * rename gausschebyshev* function * rename `gausschebyshevT` to `gausschebyshev` etc. * bump version to v0.5.2
JuliaApproximation · Oct 2, 2023 · de3eb8f · de3eb8f
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diff --git a/Project.toml b/Project.toml
@@ -1,6 +1,6 @@
 name = "FastGaussQuadrature"
 uuid = "442a2c76-b920-505d-bb47-c5924d526838"
-version = "0.5.1"
+version = "0.5.2"
 
 [deps]
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"

diff --git a/docs/src/gaussquadrature.md b/docs/src/gaussquadrature.md
@@ -53,7 +53,10 @@ There are four kinds of Gauss-Chebyshev quadrature rules, corresponding to four
 They are all have explicit simple formulas for the nodes and weights [[4]](https://books.google.co.jp/books?id=8FHf0P3to0UC).
 
 ```@docs
-gausschebyshev(n::Integer, kind::Integer)
+gausschebyshevt(n::Integer)
+gausschebyshevu(n::Integer)
+gausschebyshevv(n::Integer)
+gausschebyshevw(n::Integer)
 ```
 
 

diff --git a/src/FastGaussQuadrature.jl b/src/FastGaussQuadrature.jl
@@ -6,6 +6,10 @@ using StaticArrays
 
 export gausslegendre
 export gausschebyshev
+export gausschebyshevt
+export gausschebyshevu
+export gausschebyshevv
+export gausschebyshevw
 export gausslaguerre
 export gausshermite
 export gaussjacobi

diff --git a/src/gausschebyshev.jl b/src/gausschebyshev.jl
@@ -1,6 +1,5 @@
 @doc raw"""
-    gausschebyshev(n::Integer) -> x, w  # nodes, weights
-    gausschebyshev(n::Integer, 1) -> x, w  # nodes, weights
+    gausschebyshevt(n::Integer) -> x, w  # nodes, weights
 
 Return nodes `x` and weights `w` of [Gauss-Chebyshev quadrature](https://en.wikipedia.org/wiki/Chebyshev%E2%80%93Gauss_quadrature) of the 1st kind.
 
@@ -10,7 +9,7 @@ Return nodes `x` and weights `w` of [Gauss-Chebyshev quadrature](https://en.wiki
 
 # Examples
 ```jldoctest
-julia> x, w = gausschebyshev(3);
+julia> x, w = gausschebyshevt(3);
 
 julia> f(x) = x^4;
 
@@ -19,10 +18,16 @@ julia> I = dot(w, f.(x));
 julia> I ≈ 3π/8
 true
 ```
+"""
+function gausschebyshevt(n::Integer)
+    if n < 0
+        throw(DomainError(n, "Input n must be a non-negative integer"))
+    end
+    return [cos((2 * k - 1) * π / (2 * n)) for k = n:-1:1], fill(π / n, n)
+end
 
----
-
-    gausschebyshev(n::Integer, 2) -> x, w  # nodes, weights
+@doc raw"""
+    gausschebyshevu(n::Integer) -> x, w  # nodes, weights
 
 Return nodes `x` and weights `w` of [Gauss-Chebyshev quadrature](https://en.wikipedia.org/wiki/Chebyshev%E2%80%93Gauss_quadrature) of the 2nd kind.
 
@@ -32,7 +37,7 @@ Return nodes `x` and weights `w` of [Gauss-Chebyshev quadrature](https://en.wiki
 
 # Examples
 ```jldoctest
-julia> x, w = gausschebyshev(3, 2);
+julia> x, w = gausschebyshevu(3);
 
 julia> f(x) = x^4;
 
@@ -41,10 +46,16 @@ julia> I = dot(w, f.(x));
 julia> I ≈ π/16
 true
 ```
+"""
+function gausschebyshevu(n::Integer)
+    if n < 0
+        throw(DomainError(n, "Input n must be a non-negative integer"))
+    end
+    return [cos(k * π / (n + 1)) for k = n:-1:1], [π/(n + 1) * sin(k / (n + 1) * π)^2 for k = n:-1:1]
+end
 
----
-
-    gausschebyshev(n::Integer, 3) -> x, w  # nodes, weights
+@doc raw"""
+    gausschebyshevv(n::Integer) -> x, w  # nodes, weights
 
 Return nodes `x` and weights `w` of [Gauss-Chebyshev quadrature](https://en.wikipedia.org/wiki/Chebyshev%E2%80%93Gauss_quadrature) of the 3rd kind.
 
@@ -54,7 +65,7 @@ Return nodes `x` and weights `w` of [Gauss-Chebyshev quadrature](https://en.wiki
 
 # Examples
 ```jldoctest
-julia> x, w = gausschebyshev(3, 3);
+julia> x, w = gausschebyshevv(3);
 
 julia> f(x) = x^4;
 
@@ -63,10 +74,16 @@ julia> I = dot(w, f.(x));
 julia> I ≈ 3π/8
 true
 ```
+"""
+function gausschebyshevv(n::Integer)
+    if n < 0
+        throw(DomainError(n, "Input n must be a non-negative integer"))
+    end
+    return [cos((k - .5) * π / (n + .5)) for k = n:-1:1], [2π / (n + .5) * cos((k - .5) * π / (2 * (n + .5)))^2 for k = n:-1:1]
+end
 
----
-
-    gausschebyshev(n::Integer, 4) -> x, w  # nodes, weights
+@doc raw"""
+    gausschebyshevw(n::Integer) -> x, w  # nodes, weights
 
 Return nodes `x` and weights `w` of [Gauss-Chebyshev quadrature](https://en.wikipedia.org/wiki/Chebyshev%E2%80%93Gauss_quadrature) of the 4th kind.
 
@@ -76,7 +93,7 @@ Return nodes `x` and weights `w` of [Gauss-Chebyshev quadrature](https://en.wiki
 
 # Examples
 ```jldoctest
-julia> x, w = gausschebyshev(3, 4);
+julia> x, w = gausschebyshevw(3);
 
 julia> f(x) = x^4;
 
@@ -86,6 +103,13 @@ julia> I ≈ 3π/8
 true
 ```
 """
+function gausschebyshevw(n::Integer)
+    if n < 0
+        throw(DomainError(n, "Input n must be a non-negative integer"))
+    end
+    return [cos(k * π / (n + .5)) for k = n:-1:1], [2π / (n + .5) * sin(k * π / (2 * (n + .5)))^2 for k = n:-1:1]
+end
+
 function gausschebyshev(n::Integer, kind::Integer=1)
     # GAUSS-CHEBYSHEV NODES AND WEIGHTS.
 
@@ -95,20 +119,21 @@ function gausschebyshev(n::Integer, kind::Integer=1)
 
     # Use known explicit formulas. Complexity O(n).
     if kind == 1
-        # Gauss-ChebyshevT quadrature, i.e., w(x) = 1/sqrt(1-x^2)
-        return ([cos((2 * k - 1) * π / (2 * n)) for k = n:-1:1], fill(π / n, n))
+        # Gauss-Chebyshevt quadrature, i.e., w(x) = 1/sqrt(1-x^2)
+        Base.depwarn("`gausschebyshev(n, 1)` is deprecated and will be removed in the next breaking release. Please use `gausschebyshevt(n)` instead.", :gausschebyshev)
+        return gausschebyshevt(n)
     elseif kind == 2
-        # Gauss-ChebyshevU quadrature, i.e., w(x) = sqrt(1-x^2)
-        return ([cos(k * π / (n + 1)) for k = n:-1:1],
-                [π/(n + 1) * sin(k / (n + 1) * π)^2 for k = n:-1:1])
+        # Gauss-Chebyshevu quadrature, i.e., w(x) = sqrt(1-x^2)
+        Base.depwarn("`gausschebyshev(n, 2)` is deprecated and will be removed in the next breaking release. Please use `gausschebyshevu(n)` instead.", :gausschebyshev)
+        return gausschebyshevu(n)
     elseif kind == 3
-        # Gauss-ChebyshevV quadrature, i.e., w(x) = sqrt((1+x)/(1-x))
-        return ([cos((k - .5) * π / (n + .5)) for k = n:-1:1],
-                [2π / (n + .5) * cos((k - .5) * π / (2 * (n + .5)))^2 for k = n:-1:1])
+        # Gauss-Chebyshevv quadrature, i.e., w(x) = sqrt((1+x)/(1-x))
+        Base.depwarn("`gausschebyshev(n, 3)` is deprecated and will be removed in the next breaking release. Please use `gausschebyshevv(n)` instead.", :gausschebyshev)
+        return gausschebyshevv(n)
     elseif kind == 4
-        # Gauss-ChebyshevW quadrature, i.e., w(x) = sqrt((1-x)/(1+x))
-        return ([cos(k * π / (n + .5)) for k = n:-1:1],
-                [2π / (n + .5) * sin(k * π / (2 * (n + .5)))^2 for k = n:-1:1])
+        # Gauss-Chebyshevw quadrature, i.e., w(x) = sqrt((1-x)/(1+x))
+        Base.depwarn("`gausschebyshev(n, 4)` is deprecated and will be removed in the next breaking release. Please use `gausschebyshevw(n)` instead.", :gausschebyshev)
+        return gausschebyshevw(n)
     else
         throw(ArgumentError("Chebyshev kind should be 1, 2, 3, or 4"))
     end

diff --git a/test/test_gausschebyshev.jl b/test/test_gausschebyshev.jl
@@ -1,34 +1,42 @@
 @testset "Gauss–Chebyshev" begin
 
     @testset "Check error" begin
-        @test_throws DomainError gausschebyshev(-1,1)
-        @test_throws DomainError gausschebyshev(-1,2)
-        @test_throws DomainError gausschebyshev(-1,3)
-        @test_throws DomainError gausschebyshev(-1,4)
-        @test_throws ArgumentError gausschebyshev(0,5)
+        @test_throws DomainError gausschebyshevt(-1)
+        @test_throws DomainError gausschebyshevu(-1)
+        @test_throws DomainError gausschebyshevv(-1)
+        @test_throws DomainError gausschebyshevw(-1)
     end
 
     n = 10
 
     @testset "x.^2" begin
-        x, w = gausschebyshev(n,1)
+        x, w = gausschebyshevt(n)
         @test dot(x.^2,w) ≈ π/2
-        x, w = gausschebyshev(n,2)
+        x, w = gausschebyshevu(n)
         @test dot(x.^2,w) ≈ π/8
-        x, w = gausschebyshev(n,3)
+        x, w = gausschebyshevv(n)
         @test dot(x.^2,w) ≈ π/2
-        x, w = gausschebyshev(n,4)
+        x, w = gausschebyshevw(n)
         @test dot(x.^2,w) ≈ π/2
     end
 
     @testset "x^3" begin
-        x, w = gausschebyshev(n,1)
-        @test abs(dot(x.^3,w))<1e-15
-        x, w = gausschebyshev(n,2)
-        @test abs(dot(x.^3,w))<1e-15
-        x, w = gausschebyshev(n,3)
+        x, w = gausschebyshevt(n)
+        @test abs(dot(x.^3,w)) < 1e-15
+        x, w = gausschebyshevu(n)
+        @test abs(dot(x.^3,w)) < 1e-15
+        x, w = gausschebyshevv(n)
         @test dot(x.^3,w) ≈ 3*π/8
-        x, w = gausschebyshev(n,4)
+        x, w = gausschebyshevw(n)
         @test dot(x.^3,w) ≈ -3*π/8
     end
-end
+
+    @testset "deprecated" begin
+        n = 42
+        @test gausschebyshevt(n) == gausschebyshev(n, 1)
+        @test gausschebyshevu(n) == gausschebyshev(n, 2)
+        @test gausschebyshevv(n) == gausschebyshev(n, 3)
+        @test gausschebyshevw(n) == gausschebyshev(n, 4)
+        @test_throws ArgumentError gausschebyshev(0,5)
+    end
+end