InexactError for LinearInterpolation with one bound at -Inf

[bclyons12]

Describe the bug 🐞

In previous versions of DataInterpolations (at least v6.0), I could do a LinearInterpolation where one node was at -Inf, and as long as I asked for the value at the other node, there was no problem. Now it throws an InexactError.

Expected behavior

It should give the value at the non-infinite node.

Minimal Reproducible Example 👇

x = [-Inf, 0.0]
y = [-1.0, 1.0]
itp = DataInterpolations.LinearInterpolation(y, x)
itp(0.0) # this gave 1.0 in v6.0.0

Error & Stacktrace ⚠️

ERROR: InexactError: Int64(NaN)
Stacktrace:
  [1] Int64
    @ ./float.jl:994 [inlined]
  [2] convert
    @ ./number.jl:7 [inlined]
  [3] _round_convert
    @ ./rounding.jl:480 [inlined]
  [4] round
    @ ./rounding.jl:479 [inlined]
  [5] round
    @ ./rounding.jl:477 [inlined]
  [6] Guesser
    @ ~/.julia/packages/FindFirstFunctions/n3FjO/src/FindFirstFunctions.jl:250 [inlined]
  [7] searchsortedlastcorrelated(v::Vector{Float64}, x::Float64, guess::FindFirstFunctions.Guesser{Vector{Float64}})
    @ FindFirstFunctions ~/.julia/packages/FindFirstFunctions/n3FjO/src/FindFirstFunctions.jl:296
  [8] #get_idx#56
    @ ~/.julia/packages/DataInterpolations/C8cNn/src/interpolation_utils.jl:184 [inlined]
  [9] get_idx
    @ ~/.julia/packages/DataInterpolations/C8cNn/src/interpolation_utils.jl:179 [inlined]
 [10] _interpolate(A::DataInterpolations.LinearInterpolation{…}, t::Float64, iguess::FindFirstFunctions.Guesser{…})
    @ DataInterpolations ~/.julia/packages/DataInterpolations/C8cNn/src/interpolation_methods.jl:16
 [11] _interpolate
    @ ~/.julia/packages/DataInterpolations/C8cNn/src/interpolation_methods.jl:4 [inlined]
 [12] (::DataInterpolations.LinearInterpolation{Vector{…}, Vector{…}, Vector{…}, Vector{…}, Float64, (1,)})(t::Float64)
    @ DataInterpolations ~/.julia/packages/DataInterpolations/C8cNn/src/DataInterpolations.jl:24
 [13] top-level scope
    @ REPL[7]:1
Some type information was truncated. Use `show(err)` to see complete types.

Environment (please complete the following information):

• Output of using Pkg; Pkg.status()

Status `/private/var/folders/2s/htzp96d529l9s2yxw3_wnhdc0000gq/T/jl_UTDLH1/Project.toml`
  [82cc6244] DataInterpolations v6.6.0

• Output of using Pkg; Pkg.status(; mode = PKGMODE_MANIFEST)

Status `/private/var/folders/2s/htzp96d529l9s2yxw3_wnhdc0000gq/T/jl_UTDLH1/Manifest.toml`
  [bbf7d656] CommonSubexpressions v0.3.1
  [a8cc5b0e] Crayons v4.1.1
  [9a962f9c] DataAPI v1.16.0
  [82cc6244] DataInterpolations v6.6.0
  [e2d170a0] DataValueInterfaces v1.0.0
  [163ba53b] DiffResults v1.1.0
  [b552c78f] DiffRules v1.15.1
  [ffbed154] DocStringExtensions v0.9.3
  [64ca27bc] FindFirstFunctions v1.4.1
  [f6369f11] ForwardDiff v0.10.38
  [92d709cd] IrrationalConstants v0.2.2
  [82899510] IteratorInterfaceExtensions v1.0.0
  [692b3bcd] JLLWrappers v1.6.1
  [b964fa9f] LaTeXStrings v1.4.0
  [2ab3a3ac] LogExpFunctions v0.3.28
  [1914dd2f] MacroTools v0.5.13
  [77ba4419] NaNMath v1.0.2
  [bac558e1] OrderedCollections v1.6.3
  [aea7be01] PrecompileTools v1.2.1
  [21216c6a] Preferences v1.4.3
  [08abe8d2] PrettyTables v2.4.0
  [3cdcf5f2] RecipesBase v1.3.4
  [189a3867] Reexport v1.2.2
  [276daf66] SpecialFunctions v2.4.0
  [1e83bf80] StaticArraysCore v1.4.3
  [892a3eda] StringManipulation v0.4.0
  [3783bdb8] TableTraits v1.0.1
  [bd369af6] Tables v1.12.0
  [efe28fd5] OpenSpecFun_jll v0.5.5+0
  [0dad84c5] ArgTools v1.1.2
  [56f22d72] Artifacts v1.11.0
  [2a0f44e3] Base64 v1.11.0
  [ade2ca70] Dates v1.11.0
  [f43a241f] Downloads v1.6.0
  [7b1f6079] FileWatching v1.11.0
  [b27032c2] LibCURL v0.6.4
  [76f85450] LibGit2 v1.11.0
  [8f399da3] Libdl v1.11.0
  [37e2e46d] LinearAlgebra v1.11.0
  [56ddb016] Logging v1.11.0
  [d6f4376e] Markdown v1.11.0
  [ca575930] NetworkOptions v1.2.0
  [44cfe95a] Pkg v1.11.0
  [de0858da] Printf v1.11.0
  [9a3f8284] Random v1.11.0
  [ea8e919c] SHA v0.7.0
  [fa267f1f] TOML v1.0.3
  [a4e569a6] Tar v1.10.0
  [cf7118a7] UUIDs v1.11.0
  [4ec0a83e] Unicode v1.11.0
  [e66e0078] CompilerSupportLibraries_jll v1.1.1+0
  [deac9b47] LibCURL_jll v8.6.0+0
  [e37daf67] LibGit2_jll v1.7.2+0
  [29816b5a] LibSSH2_jll v1.11.0+1
  [c8ffd9c3] MbedTLS_jll v2.28.6+0
  [14a3606d] MozillaCACerts_jll v2023.12.12
  [4536629a] OpenBLAS_jll v0.3.27+1
  [05823500] OpenLibm_jll v0.8.1+2
  [83775a58] Zlib_jll v1.2.13+1
  [8e850b90] libblastrampoline_jll v5.11.0+0
  [8e850ede] nghttp2_jll v1.59.0+0
  [3f19e933] p7zip_jll v17.4.0+2

• Output of versioninfo()

Julia Version 1.11.1
Commit 8f5b7ca12ad (2024-10-16 10:53 UTC)
Build Info:
  Official https://julialang.org/ release
Platform Info:
  OS: macOS (x86_64-apple-darwin22.4.0)
  CPU: 8 × Intel(R) Core(TM) i7-1068NG7 CPU @ 2.30GHz
  WORD_SIZE: 64
  LLVM: libLLVM-16.0.6 (ORCJIT, icelake-client)
Threads: 8 default, 0 interactive, 4 GC (on 8 virtual cores)
Environment:
  JULIA_EDITOR = code
  JULIA_NUM_THREADS = 8

Additional context

Making @orso82 aware

[ChrisRackauckas]

I did not know we ever supported this 😅 . If it worked it worked unintentionally, though we could see if we could add that. I presume that beyond linear and constant interpolations though it might be hard to guarantee support for.

[bclyons12]

We handled it on our side to prevent -Inf from appearing in the input array, but it's a change of behavior in an edge case that wound up breaking our code.

[SouthEndMusic]

Interesting, I've always used nextfloat(-Inf) to prevent problems like this.

[bclyons12]

@SouthEndMusic that's exactly what we wound up using in our application