Ensure that binomlogpdf returns non-positive values, t distribution…

…s with infinite parameter are supported, and add integration tests (#126)

* Ensure that `binomlogpdf` returns non-positive values

* Add test

* Add integration test

* Bump version

* Handle student t distribution with infinite `ν`

.github/workflows/IntegrationTest.yml

@@ -0,0 +1,52 @@
+name: IntegrationTest
+
+on:
+ pull_request:
+ branches:
+ - master
+ push:
+ branches:
+ - master
+ tags: '*'
+
+jobs:
+ test:
+ name: ${{ matrix.package.repo }}/${{ matrix.package.group }}
+ runs-on: ${{ matrix.os }}
+ strategy:
+ fail-fast: false
+ matrix:
+ julia-version: [1]
+ os: [ubuntu-latest]
+ package:
+ - {user: JuliaStats, repo: Distributions.jl}
+
+ steps:
+ - uses: actions/checkout@v2
+ - uses: julia-actions/setup-julia@v1
+ with:
+ version: ${{ matrix.julia-version }}
+ arch: x64
+ - uses: julia-actions/julia-buildpkg@latest
+ - name: Clone Downstream
+ uses: actions/checkout@v2
+ with:
+ repository: ${{ matrix.package.user }}/${{ matrix.package.repo }}
+ path: downstream
+ - name: Load this and run the downstream tests
+ shell: julia --color=yes --project=downstream {0}
+ run: |
+ using Pkg
+ try
+ # force it to use this PR's version of the package
+ Pkg.develop(PackageSpec(path=".")) # resolver may fail with main deps
+ Pkg.update()
+ Pkg.test() # resolver may fail with test time deps
+ catch err
+ err isa Pkg.Resolve.ResolverError || rethrow()
+ # If we can't resolve that means this is incompatible by SemVer and this is fine
+ # It means we marked this as a breaking change, so we don't need to worry about
+ # Mistakenly introducing a breaking change, as we have intentionally made one
+ @info "Not compatible with this release. No problem." exception=err
+ exit(0) # Exit immediately, as a success
+ end

Project.toml

@@ -1,6 +1,6 @@
 name = "StatsFuns"
 uuid = "4c63d2b9-4356-54db-8cca-17b64c39e42c"
-version = "0.9.11"
+version = "0.9.12"
 
 [deps]
 ChainRulesCore = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"

src/distrs/binom.jl

@@ -19,6 +19,6 @@ binompdf(n::Real, p::Real, k::Real) = exp(binomlogpdf(n, p, k))
 binomlogpdf(n::Real, p::Real, k::Real) = binomlogpdf(promote(n, p, k)...)
 function binomlogpdf(n::T, p::T, k::T) where {T<:Real}
  m = clamp(k, 0, n)
- val = betalogpdf(m + 1, n - m + 1, p) - log(n + 1)
+ val = min(0, betalogpdf(m + 1, n - m + 1, p) - log(n + 1))
  return 0 <= k <= n && isinteger(k) ? val : oftype(val, -Inf)
 end

src/distrs/tdist.jl

@@ -17,6 +17,7 @@ tdistpdf(ν::Real, x::Real) = exp(tdistlogpdf(ν, x))
 
 tdistlogpdf(ν::Real, x::Real) = tdistlogpdf(promote(ν, x)...)
 function tdistlogpdf(ν::T, x::T) where {T<:Real}
+ isinf(ν) && return normlogpdf(x)
  νp12 = (ν + 1) / 2
  return loggamma(νp12) - (logπ + log(ν)) / 2 - loggamma(ν / 2) - νp12 * log1p(x^2 / ν)
 end

test/misc.jl

@@ -63,3 +63,10 @@ end
  @test binomlogpdf(1, 0.5, prevfloat(1.0)) == -Inf
  @test binomlogpdf(1, 0.5, nextfloat(1.0)) == -Inf
 end
+
+@testset "binom special cases" begin
+ for (n, p, k) in ((5, 0.0, 0), (5, 1.0, 5))
+ @test iszero(binomlogpdf(n, p, k))
+ @test isone(binompdf(n, p, k))
+ end
+end

test/rmath.jl

@@ -301,6 +301,8 @@ end
  ((1,), -5f0:0.1f0:5f0),
  ((1,), -Float16(5):Float16(0.1):Float16(5)),
  ((1,), -5//1:5//1),
+ ((Inf,), -5.0:0.1:5.0),
+ ((Inf32,), -5f0:0.1f0:5f0),
  ])
 
  rmathcomp_tests("srdist", [