Add Age and Interval types

Project.toml

@@ -1,7 +1,7 @@
 name = "Isoplot"
 uuid = "5adc30d5-9ddf-423c-bb15-ece697bec3ab"
 authors = ["C. Brenhin Keller <[email protected]>"]
-version = "0.3.1"
+version = "0.3.2"
 
 [deps]
 Distributions = "31c24e10-a181-5473-b8eb-7969acd0382f"

src/Isoplot.jl

@@ -17,7 +17,7 @@ module Isoplot
 
     # Abstract types which we'll subtype later
     include("analysis.jl")
-    export age, ratio, ellipse, CI
+    export age, ratio, ellipse, CI, Age, Interval
 
     include("regression.jl")
     export wmean, awmean, gwmean, distwmean, mswd

src/analysis.jl

@@ -9,6 +9,27 @@ ratio(t::Number, λ::Number) = exp(λ*t) - 1
 # Extend Base.isnan to return true if any component of the Analysis is NaN
 Base.isnan(a::Analysis) = any(isnan, a.μ) || any(isnan, a.σ) || any(isnan, a.Σ)
 
+# A moment in time
+struct Age{T<:AbstractFloat}
+    mean::T
+    sigma::T
+end
+Age(μ, σ) = Age(float(μ), float(σ))
+Age(x) = Age(val(x), err(x))
+
+# A duration of time
+struct Interval{T<:AbstractFloat}
+    min::T
+    min_sigma::T
+    max::T
+    max_sigma::T
+end
+Interval(lμ, lσ, uμ, uσ) = Interval(float(lμ), float(lσ), float(uμ), float(uσ))
+Interval(l, u) = Interval(val(l), err(l), val(u), err(u))
+Base.min(x::Interval{T}) where {T} = Age{T}(x.min, x.min_sigma) 
+Base.max(x::Interval{T}) where {T} = Age{T}(x.max, x.max_sigma)
+
+# A confidence or credible interval with 95% bounds
 struct CI{T<:AbstractFloat}
     mean::T
     sigma::T
@@ -83,6 +104,12 @@ end
 # Generic fallback methods for things that don't have uncertainties
 val(x) = x
 err(x::T) where {T} = zero(T)
+# Specialized methods for `CI`s
+val(x::CI{T}) where {T} = x.mean::T
+err(x::CI{T}) where {T} = x.sigma::T
+# Specialized methods for `Age`s
+val(x::Age{T}) where {T} = x.mean::T
+err(x::Age{T}) where {T} = x.sigma::T
 # Specialized methods for `Measurement`s
-val(m::Measurement{T}) where {T} = m.val::T
-err(m::Measurement{T}) where {T} = m.err::T
+val(x::Measurement{T}) where {T} = x.val::T
+err(x::Measurement{T}) where {T} = x.err::T

test/runtests.jl

@@ -17,10 +17,24 @@ using Measurements
 end
 
 @testset "General" begin
-    @test Isoplot.val(1±1) === 1.0
-    @test Isoplot.err(1±1) === 1.0
+    @test Age(0) isa Age{Float64}
+    @test Age(0, 1) isa Age{Float64}
+    @test Interval(0, 1) isa Interval{Float64}
+    @test Interval(0, 1) === Interval(0,0, 1,0)
+    @test min(Interval(0, 1)) isa Age{Float64}
+    @test max(Interval(0, 1)) isa Age{Float64}
+    @test min(Interval(0, 1)) === Age(0,0) === Age(0)
+    @test max(Interval(0, 1)) === Age(1,0) === Age(1)
     @test Isoplot.val(1) === 1
     @test Isoplot.err(1) === 0
+    @test Isoplot.val(1±1) === 1.0
+    @test Isoplot.err(1±1) === 1.0
+    ci = CI(1:10)
+    @test Isoplot.val(ci) ≈ 5.5
+    @test Isoplot.err(ci) ≈ 3.0276503540974917
+    a = Age(ci)
+    @test Isoplot.val(a) ≈ 5.5
+    @test Isoplot.err(a) ≈ 3.0276503540974917
 end
 
 @testset "U-Pb" begin