add Remainder, still need the tests

src/transforms/remainder.jl

@@ -10,18 +10,74 @@ and returns a new table with an additional column containing the
 remainder value `xₙ₊₁ = total .- (x₁ + x₂ + ⋯ + xₙ)` If the `total`
 value is not specified, then default to the maximum sum across rows.
 """
-struct Remainder <: Transform end
+struct Remainder <: Transform
+ total::Union{Float64,Nothing}
+end
+
+Remainder(total=nothing) = Remainder(total)
 
 isrevertible(::Type{Remainder}) = true
 
-function apply(::Remainder, table)
- # TODO
+assertions(::Type{Remainder}) = [TT.assert_continuous]
+
+function apply(transform::Remainder, table)
+ # basic checks
+ for assertion in assertions(transform)
+ assertion(table)
+ end
+
+ # design matrix
+ X = Tables.matrix(table)
+
+ # find total across rows
+ total = if !isnothing(transform.total)
+ transform.total
+ else
+ maximum(sum(X, dims=2))
+ end
+
+ # original column names
+ names = Tables.columnnames(table)
+
+ # create a column with the remainder of each row
+ T = total .- S
+ Z = hcat(X, T)
+
+ # table with the new column
+ names = (names..., :remainder)
+ 𝒯 = (; zip(names, eachcol(Z))...)
+
+ newtable = 𝒯 |> Tables.materializer(table)
+ newtable, total
 end
 
 function revert(::Remainder, newtable, cache)
- # TODO
+ TT.Reject(:remainder)(newtable)
 end
 
-function reapply(::Remainder, table, cache)
- # TODO
+function reapply(transform::Remainder, table, cache)
+ # basic checks
+ for assertion in assertions(transform)
+ assertion(table)
+ end
+
+ # retrieve total from cache
+ total = cache
+
+ # original column names
+ names = Tables.columnnames(table)
+
+ # design matrix
+ X = Tables.matrix(table)
+
+ # create a column with the remainder
+ S = sum(X, dims=2)
+ Z = [X (total .- S)]
+
+ # table with the new column
+ names = (names..., :remainder)
+ 𝒯 = (; zip(names, eachcol(Z))...)
+
+ newtable = 𝒯 |> Tables.materializer(table)
+ newtable, total
 end

test/transforms.jl

@@ -29,4 +29,17 @@
  tilr = revert(ILR(:b), n, c)
  @test n |> Tables.columnnames == (:a, :c)
  @test tilr |> Tables.columnnames == (:a, :b, :c)
+
+ # Tests for Remainder
+ t = (a=rand(100), b=rand(100), c=rand(100))
+ n, c = apply(Remainder(), t)
+ trem = revert(Remainder(), n, c)
+ @test Tables.matrix(n)[:, 1:end-1] == Tables.matrix(t)
+ @test all(x -> 0 ≤ x ≤ c, Tables.matrix(n)[:, end])
+ @test n |> Tables.columnnames == (:a, :b, :c, :remainder)
+ @test trem |> Tables.columnnames == (:a, :b, :c)
+
+ t = (a=rand(100), b=rand(100), c=rand(100))
+ n, c = reapply(Remainder(), t, c)
+ @test all(x -> 0 ≤ x ≤ c, Tables.matrix(n)[:, end])
 end