Fix beta_inc_inv bug introduced in #399 (#401)

JuliaMath · Jun 1, 2022 · 49be7e6 · 49be7e6 · devmotion · Jun 1, 2022
1 parent 7461b51
commit 49be7e6
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Showing 3 changed files with 8 additions and 2 deletions.
diff --git a/Project.toml b/Project.toml
@@ -1,6 +1,6 @@
 name = "SpecialFunctions"
 uuid = "276daf66-3868-5448-9aa4-cd146d93841b"
-version = "2.1.5"
+version = "2.1.6"
 
 [deps]
 ChainRulesCore = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"

diff --git a/src/beta_inc.jl b/src/beta_inc.jl
@@ -967,7 +967,7 @@ function _beta_inc_inv(a::Float64, b::Float64, p::Float64, q::Float64=1-p)
     sq = 1.0
     prev = 1.0
 
-    x = clamp(x, fpu, prevfloat(1.0))
+    x = clamp(x, 0.0001, 0.9999)
 
     # This first argument was proposed in
     #

diff --git a/test/beta_inc.jl b/test/beta_inc.jl
@@ -305,4 +305,10 @@ end
         y = 2.0e-280
         @test beta_inc(2.0, 1.0, beta_inc_inv(2.0, 1.0, y, 1.0)[1])[1] ≈ y
     end
+
+    @testset "StatsFuns#145" begin
+        y = 0.92
+        @test beta_inc_inv(0.01, 0.1, y)[1] ≈ 0.7803014210919872
+        @test beta_inc(0.01, 0.1, beta_inc_inv(0.01, 0.1, y)[1])[1] ≈ y
+    end
 end