Merge pull request #107 from ChrisRackauckas/patch-1

add eps

src/Unitful.jl

@@ -8,7 +8,7 @@ import Base: min, max, floor, ceil, real, imag, conj
 import Base: exp, exp10, exp2, expm1, log, log10, log1p, log2
 import Base: sin, cos, tan, cot, sec, csc, atan2, cis, vecnorm
 
-import Base: mod, rem, div, fld, cld, trunc, round, sign, signbit
+import Base: eps, mod, rem, div, fld, cld, trunc, round, sign, signbit
 import Base: isless, isapprox, isinteger, isreal, isinf, isfinite, isnan
 import Base: copysign, flipsign
 import Base: prevfloat, nextfloat, maxintfloat, rat, step

src/quantities.jl

@@ -280,6 +280,9 @@ isfinite(x::Quantity) = isfinite(x.val)
 isinf(x::Quantity) = isinf(x.val)
 isnan(x::Quantity) = isnan(x.val)
 
+eps(x::T) where {T<:Quantity} = T(eps(x.val))
+eps(x::Type{T}) where {T<:Quantity} = T(eps(Unitful.numtype(T)))
+
 unsigned(x::Quantity) = Quantity(unsigned(x.val), unit(x))
 
 for f in (:exp, :exp10, :exp2, :expm1, :log, :log10, :log1p, :log2)

test/runtests.jl

@@ -529,6 +529,10 @@ end
         @test !isapprox(1.0u"m", 1.1u"m"; atol=50u"mm")
         @test isapprox(1.0u"m", 1.1u"m"; rtol=0.2)
         @test !isapprox(1.0u"m", 1.1u"m"; rtol=0.05)
+
+        # Test eps
+        @test eps(1.0u"s") == eps(1.0)u"s"
+        @test eps(typeof(1.0u"s")) == eps(Float64)u"s"
 
         # Test promotion behavior
         @test !isapprox(1.0u"m", 1.0u"s")