Merge pull request #57 from andreasnoack/an/fix

Use max instead of + when combining abs- and relstep.
JuliaDiff · May 29, 2019 · 8a9f60d · 8a9f60d
2 parents 7616865 + a07a909
commit 8a9f60d
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/src/finitediff.jl b/src/finitediff.jl
@@ -7,11 +7,11 @@ Compute the finite difference interval epsilon.
 Reference: Numerical Recipes, chapter 5.7.
 =#
 @inline function compute_epsilon(::Type{Val{:forward}}, x::T, relstep::Real, absstep::Real) where T<:Number
-    return relstep*abs(x) + absstep
+    return max(relstep*abs(x), absstep)
 end
 
 @inline function compute_epsilon(::Type{Val{:central}}, x::T, relstep::Real, absstep::Real) where T<:Number
-    return relstep*abs(x) + absstep
+    return max(relstep*abs(x), absstep)
 end
 
 @inline function compute_epsilon(::Type{Val{:complex}}, x::T, ::Union{Nothing,T}=nothing, ::Union{Nothing,T}=nothing) where T<:Real