logic error in ncbeta, (so in ncF too)

[JeffreySarnoff]

julia> ncbeta(0.5, 0.25, 0.125, 0.875 )
ERROR: UndefVarError: ans not defined
Stacktrace:
 [1] beta_integrand(a::Float64, b::Float64, x::Float64, y::Float64, mu::Float64)
   @ SpecialFunctions ~\.julia\packages\SpecialFunctions\LC8dm\src\beta_inc.jl:159
 [2] beta_integrand
   @ ~\.julia\packages\SpecialFunctions\LC8dm\src\beta_inc.jl:95 [inlined]
 [3] ncbeta_tail(a::Float64, b::Float64, lambda::Float64, x::Float64)
   @ SpecialFunctions ~\.julia\packages\SpecialFunctions\LC8dm\src\betanc.jl:29
 [4] ncbeta(a::Float64, b::Float64, lambda::Float64, x::Float64)
   @ SpecialFunctions ~\.julia\packages\SpecialFunctions\LC8dm\src\betanc.jl:162
 [5] top-level scope
   @ REPL[74]:1

julia> ncF(0.5, 0.25, 0.125, 0.875 )
ERROR: UndefVarError: ans not defined
Stacktrace:
 [1] beta_integrand(a::Float64, b::Float64, x::Float64, y::Float64, mu::Float64)
   @ SpecialFunctions ~\.julia\packages\SpecialFunctions\LC8dm\src\beta_inc.jl:159
 [2] beta_integrand
   @ ~\.julia\packages\SpecialFunctions\LC8dm\src\beta_inc.jl:95 [inlined]
 [3] ncbeta_tail(a::Float64, b::Float64, lambda::Float64, x::Float64)
   @ SpecialFunctions ~\.julia\packages\SpecialFunctions\LC8dm\src\betanc.jl:29
 [4] ncbeta
   @ ~\.julia\packages\SpecialFunctions\LC8dm\src\betanc.jl:162 [inlined]
 [5] ncF(x::Float64, v1::Float64, v2::Float64, lambda::Float64)
   @ SpecialFunctions ~\.julia\packages\SpecialFunctions\LC8dm\src\betanc.jl:180
 [6] top-level scope
   @ REPL[75]:1

julia> versioninfo()
Julia Version 1.6.0-DEV.771
Commit 0336f672db (2020-08-30 01:07 UTC)
Platform Info:
  OS: Windows (x86_64-w64-mingw32)
  CPU: Intel(R) Xeon(R) E-2176M  CPU @ 2.70GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-9.0.1 (ORCJIT, skylake)
Environment:
  JULIA_NUM_THREADS = 8

[stevengj]

Seems to have been introduced in #165. @Sumegh-git, do you have a fix?

[awadell1]

Looks like I've hit a similar error (Version [276daf66] SpecialFunctions v1.3.0)

julia> beta_inc(0.04401630888685953, 0.026187091737271025, 0.707)
ERROR: UndefVarError: ans not defined
Stacktrace:
 [1] beta_integrand(a::Float64, b::Float64, x::Float64, y::Float64, mu::Float64)
   @ SpecialFunctions ~/.julia/packages/SpecialFunctions/mFAQ4/src/beta_inc.jl:162
 [2] beta_inc_diff(a::Float64, b::Float64, x::Float64, y::Float64, n::Int64, epps::Float64)
   @ SpecialFunctions ~/.julia/packages/SpecialFunctions/mFAQ4/src/beta_inc.jl:619
 [3] beta_inc(a::Float64, b::Float64, x::Float64, y::Float64)
   @ SpecialFunctions ~/.julia/packages/SpecialFunctions/mFAQ4/src/beta_inc.jl:853
 [4] beta_inc(a::Float64, b::Float64, x::Float64)
   @ SpecialFunctions ~/.julia/packages/SpecialFunctions/mFAQ4/src/beta_inc.jl:863
 [5] top-level scope
   @ REPL[89]:1

Version Info

julia> versioninfo()
Julia Version 1.6.0
Commit f9720dc2eb (2021-03-24 12:55 UTC)
Platform Info:
  OS: macOS (x86_64-apple-darwin19.6.0)
  CPU: Apple M1
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-11.0.1 (ORCJIT, westmere)

Is anyone working this or can I take a crack?

[giordano]

Is anyone working this

I don't think anyone claimed it

or can I take a crack?

That'd be great! It looks like ans is defined in some ifs, but not in all branches, so depending on the condition ans may not be defined. It's always a bit weird to name a variable ans in Julia

[devmotion]

All examples above work correctly with SpecialFunctions 1.4.1. The bug was fixed by @andreasnoack in #316, the diff shows the fixes in beta_integrand (https://github.com/JuliaMath/SpecialFunctions.jl/pull/316/files#diff-7b91342b259418c7f2d359de126c34ee2f21d4c47bcd0384461696d90f1569a0).