Implement logarithmic quantities

.travis.yml

@@ -2,7 +2,7 @@
 language: julia
 os:
   - linux
-  - osx
+#  - osx    # locally test on my MacBook Pro; OS X tests take too long on Travis CI
 julia:
   - 0.6
   - nightly
@@ -19,6 +19,6 @@ after_success:
   # push coverage results to Coveralls
   - julia -e 'cd(Pkg.dir("Unitful")); Pkg.add("Coverage"); using Coverage; Coveralls.submit(Coveralls.process_folder())'
   # push coverage results to Codecov
-  - julia -e 'cd(Pkg.dir("Unitful")); Pkg.add("Coverage"); using Coverage; Codecov.submit(process_folder())'
+  - julia -e 'cd(Pkg.dir("Unitful")); using Coverage; Codecov.submit(process_folder())'
   - julia -e 'Pkg.add("Documenter")'
   - julia -e 'cd(Pkg.dir("Unitful")); include(joinpath("docs", "make.jl"))'

NEWS.md

@@ -1,3 +1,14 @@
+- v0.4.0
+  - Introduce logarithmic quantities.
+  - Update syntax for Julia 0.6 and reorganize code for clarity.
+  - Redefine `ustrip(x::Quantity) = ustrip(x.val)`. In most cases, this is unlikely to
+    affect user code. The generic fallback `ustrip(x::Number)` remains unchanged.
+  - `isapprox(1.0u"m",5)` returns `false` instead of throwing a `DimensionError`,
+    in keeping with the behavior of an equality check (`==`).
+  - Deprecated `dimension(x::AbstractArray{T}) where T<:Number`, use broadcasting instead.
+  - Deprecated `dimension(x::AbstractArray{T}) where T<:Units`, use broadcasting instead.
+  - Deprecated `ustrip(A::AbstractArray{T}) where T<:Number`, use broadcasting instead.
+  - Deprecated `ustrip(A::AbstractArray{T}) where T<:Quantity`, use broadcasting instead.
 - v0.3.0
   - Require Julia 0.6
   - Adds overloads for `rand` and `ones` [#96](https://github.com/ajkeller34/Unitful.jl/issues/96).

docs/make.jl

@@ -4,7 +4,7 @@ makedocs()
 
 deploydocs(
     deps   = Deps.pip("mkdocs", "mkdocs-material", "python-markdown-math"),
-    julia  = "nightly",
+    julia  = "0.6",
     osname = "linux",
     repo   = "github.com/ajkeller34/Unitful.jl.git"
 )

docs/mkdocs.yml

@@ -1,7 +1,7 @@
 site_name:        Unitful.jl
 repo_url:         https://github.com/ajkeller34/Unitful.jl
-site_description: Package for units.
-site_author:      Andrew Keller
+site_description: Performant and expressive calculations with arbitrary units.
+site_author:      Andrew J. Keller
 
 theme: material
 extra:
@@ -33,6 +33,7 @@ pages:
 - Conversion / promotion: conversion.md
 - Manipulating units: manipulations.md
 - How units are displayed: display.md
+- Logarithmic scales: logarithm.md
 - Extending Unitful: extending.md
 - Troubleshooting: trouble.md
 - License: LICENSE.md

docs/src/highlights.md

@@ -9,21 +9,21 @@ end
 Consider the following toy example, converting from voltage or power ratios to decibels:
 
 ```jldoctest
-julia> dB(num::Unitful.Voltage, den::Unitful.Voltage) = 20*log10(num/den)
- dB (generic function with 1 method)
+julia> whatsit(x::Unitful.Voltage) = "voltage!"
+ whatsit (generic function with 1 method)
 
-julia> dB(num::Unitful.Power, den::Unitful.Power) = 10*log10(num/den)
- dB (generic function with 2 methods)
+julia> whatsit(x::Unitful.Length) = "length!"
+ whatsit (generic function with 2 methods)
 
-julia> dB(1u"mV", 1u"V")
--60.0
+julia> whatsit(1u"mm")
+"length!"
 
-julia> dB(1u"mW", 1u"W")
--30.0
-```
+julia> whatsit(1u"kV")
+"voltage!"
 
-We don't currently implement dB as a unit because the log scale would require
-special treatment, but it is under consideration.
+julia> whatsit(1u"A" * 2.5u"Ω")
+"voltage!"
+```
 
 ### Dimensions in a type definition
 
@@ -79,6 +79,13 @@ julia> Diagonal([-1.0u"c^2", 1.0, 1.0, 1.0])
        ⋅    ⋅    ⋅   1.0
 ```
 
+## Logarithmic units
+
+```jldoctest
+julia> uconvert(u"mW*s", 20u"dBm/Hz")
+100.0 s mW
+```
+
 ## Units with rational exponents
 
 ```jldoctest

docs/src/index.md

@@ -16,19 +16,11 @@ We want to support not only SI units but also any other unit system. We also
 want to minimize or in some cases eliminate the run-time penalty of units.
 There should be facilities for dimensional analysis. All of this should
 integrate easily with the usual mathematical operations and collections
-that are found in Julia base.
-
-!!! note
-    If you have been previously using Unitful 0.0.4 or earlier, the defaults
-    mechanism has been completely rewritten. This means you will now need to
-    define new units in your `.juliarc.jl` file or in a new module. See
-    [Defining new units](@ref) and [Extending Unitful](@ref) for details.
-    Additionally, to specify custom rules for promotion, see
-    [Basic promotion mechanisms](@ref) and [Advanced promotion mechanisms](@ref).
+that are defined in Julia.
 
 ## Quick start
 
-- This package requires Julia 0.5. Older versions will not be supported.
+- This package requires Julia 0.6. Older versions will not be supported.
 - `Pkg.add("Unitful")`
 - `using Unitful`