Move StatsBase describe code from DataTables to NullableArrays (#191)

Makes minor adjustments to make former DataTables printing more
like StatsBase.

REQUIRE

@@ -1,3 +1,4 @@
 julia 0.5
 Compat 0.19.0
 Reexport
+StatsBase 0.14

src/NullableArrays.jl

@@ -5,6 +5,7 @@ module NullableArrays
 using Compat
 using Compat.view
 using Reexport
+using StatsBase
 @reexport using Base.Cartesian
 
 export NullableArray,
@@ -33,5 +34,6 @@ include("reduce.jl")
 include("show.jl")
 include("subarray.jl")
 include("deprecated.jl")
+include("utils.jl")
 
 end

src/utils.jl

@@ -0,0 +1,53 @@
+StatsBase.describe(X::NullableVector) = StatsBase.describe(STDOUT, X)
+
+function StatsBase.describe{T<:Real}(io::IO, X::NullableVector{T})
+ nullcount = sum(X.isnull)
+ pnull = 100nullcount/length(X)
+ if pnull != 100 # describe will fail if dropnull returns an empty vector
+ describe(io, dropnull(X))
+ else
+ println(io, "Summary Stats:")
+ println(io, "Type: $(eltype(X))")
+ end
+ println(io, "Number Missing: $(nullcount)")
+ @printf(io, "%% Missing: %.6f\n", pnull)
+ return
+end
+
+function StatsBase.describe(io::IO, X::NullableVector)
+ nullcount = sum(X.isnull)
+ pnull = 100nullcount/length(X)
+ println(io, "Summary Stats:")
+ println(io, "Length: $(length(X))")
+ println(io, "Type: $(eltype(X))")
+ println(io, "Number Unique: $(length(unique(X)))")
+ println(io, "Number Missing: $(nullcount)")
+ @printf(io, "%% Missing: %.6f\n", pnull)
+ return
+end
+
+function StatsBase.describe{T<:Real}(io::IO, X::AbstractVector{Nullable{T}})
+ nullcount = sum(_isnull, X)
+ pnull = 100nullcount/length(X)
+ if pnull != 100 # describe will fail if dropnull returns an empty vector
+ describe(io, dropnull(X))
+ else
+ println(io, "Summary Stats:")
+ println(io, "Type: $(eltype(X))")
+ end
+ println(io, "Number Missing: $(nullcount)")
+ @printf(io, "%% Missing: %.6f\n", pnull)
+ return
+end
+
+function StatsBase.describe{T<:Nullable}(io::IO, X::AbstractVector{T})
+ nullcount = sum(_isnull, X)
+ pnull = 100nullcount/length(X)
+ println(io, "Summary Stats:")
+ println(io, "Length: $(length(X))")
+ println(io, "Type: $(eltype(X))")
+ println(io, "Number Unique: $(length(unique(X)))")
+ println(io, "Number Missing: $(nullcount)")
+ @printf(io, "%% Missing: %.6f\n", pnull)
+ return
+end

test/runtests.jl

@@ -17,6 +17,7 @@ my_tests = [
  "operators.jl",
  "subarray.jl",
  "show.jl",
+ "utils.jl"
 ]
 
 println("Running tests:")

test/utils.jl

@@ -0,0 +1,110 @@
+module TestUtils
+ using StatsBase
+ using Base.Test
+ using NullableArrays
+
+ @testset "describe" begin
+ io = IOBuffer()
+ describe(io, NullableArray(1:10))
+ @test String(take!(io)) == """
+ Summary Stats:
+ Mean: 5.500000
+ Minimum: 1.000000
+ 1st Quartile: 3.250000
+ Median: 5.500000
+ 3rd Quartile: 7.750000
+ Maximum: 10.000000
+ Length: 10
+ Type: $Int
+ Number Missing: 0
+ % Missing: 0.000000
+ """
+ describe(io, NullableArray([1, Nullable()]))
+ @test String(take!(io)) == """
+ Summary Stats:
+ Mean: 1.000000
+ Minimum: 1.000000
+ 1st Quartile: 1.000000
+ Median: 1.000000
+ 3rd Quartile: 1.000000
+ Maximum: 1.000000
+ Length: 1
+ Type: $Int
+ Number Missing: 1
+ % Missing: 50.000000
+ """
+ describe(io, NullableArray(["s"]))
+ @test String(take!(io)) == """
+ Summary Stats:
+ Length: 1
+ Type: Nullable{String}
+ Number Unique: 1
+ Number Missing: 0
+ % Missing: 0.000000
+ """
+ describe(io, NullableArray(["s", Nullable()]))
+ @test String(take!(io)) == """
+ Summary Stats:
+ Length: 2
+ Type: Nullable{String}
+ Number Unique: 2
+ Number Missing: 1
+ % Missing: 50.000000
+ """
+ describe(io, ["s", Nullable()])
+ @test String(take!(io)) == """
+ Summary Stats:
+ Length: 2
+ Type: Nullable{String}
+ Number Unique: 2
+ Number Missing: 1
+ % Missing: 50.000000
+ """
+ describe(io, [1, Nullable()])
+ @test String(take!(io)) == """
+ Summary Stats:
+ Mean: 1.000000
+ Minimum: 1.000000
+ 1st Quartile: 1.000000
+ Median: 1.000000
+ 3rd Quartile: 1.000000
+ Maximum: 1.000000
+ Length: 1
+ Type: $Int
+ Number Missing: 1
+ % Missing: 50.000000
+ """
+ describe(io, NullableArray{Any}(5))
+ @test String(take!(io)) == """
+ Summary Stats:
+ Length: 5
+ Type: Nullable{Any}
+ Number Unique: 1
+ Number Missing: 5
+ % Missing: 100.000000
+ """
+ describe(io, NullableArray{Float64}(5))
+ @test String(take!(io)) == """
+ Summary Stats:
+ Type: Nullable{Float64}
+ Number Missing: 5
+ % Missing: 100.000000
+ """
+ describe(io, fill(Nullable{String}(), 5))
+ @test String(take!(io)) == """
+ Summary Stats:
+ Length: 5
+ Type: Nullable{String}
+ Number Unique: 1
+ Number Missing: 5
+ % Missing: 100.000000
+ """
+ describe(io, fill(Nullable{Float64}(), 5))
+ @test String(take!(io)) == """
+ Summary Stats:
+ Type: Nullable{Float64}
+ Number Missing: 5
+ % Missing: 100.000000
+ """
+ end
+end