Switch to positional interface

src/LearnBase.jl

@@ -1,17 +1,16 @@
 module LearnBase
 
-import StatsBase
-using StatsBase: nobs
+import StatsBase: nobs
 
 # AGGREGATION MODES
 include("aggmode.jl")
 
-# VIEW AND ITERATORS
-include("iteration.jl")
-
 # OBSERVATION DIMENSIONS
 include("observation.jl")
 
+# LABEL ENCONDINGS
+include("labels.jl")
+
 # LEARNING COSTS (e.g. loss & penalty)
 include("costs.jl")
 

src/observation.jl

@@ -14,7 +14,7 @@ default_obsdim(A::AbstractArray) = ndims(A)
 default_obsdim(tup::Tuple) = map(default_obsdim, tup)
 
 """
-   getobs(data, idx; obsdim = default_obsdim(data))
+   getobs(data, idx, obsdim = default_obsdim(data))
 
 Return the observations corresponding to the observation-index `idx`.
 Note that `idx` can be of type `Int` or `AbstractVector`.
@@ -24,7 +24,7 @@ The returned observation(s) should be in the form intended to
 be passed as-is to some learning algorithm. There is no strict
 interface requirement on how this "actual data" must look like.
 Every author behind some custom data container can make this
-decision himself/herself. We do, however, expect it to be consistent
+decision themselves. We do, however, expect it to be consistent
 for `idx` being an integer, as well as `idx` being an abstract
 vector, respectively.
 
@@ -33,10 +33,11 @@ to indicate which dimension of `data` denotes the observations.
 See [`default_obsdim`](@ref) for defining a default dimension.
 """
 function getobs end
-getobs(data, idx; obsdim) = getobs(data, idx)
+getobs(data, idx) = data[idx]
+getobs(data, idx, obsdim) = getobs(data, idx)
 
 """
-   getobs!(buffer, data, idx; obsdim = default_obsdim(obsdim))
+   getobs!(buffer, data, idx, obsdim = default_obsdim(obsdim))
 
 Inplace version of `getobs(data, idx; obsdim)`. If this method
 is defined for the type of `data`, then `buffer` should be used
@@ -54,7 +55,7 @@ to indicate which dimension of `data` denotes the observations.
 See [`default_obsdim`](@ref) for defining a default dimension.
 """
 function getobs! end
-getobs!(buffer, data, idx; obsdim = default_obsdim(data)) = getobs(data, idx; obsdim = obsdim)
+getobs!(buffer, data, idx, obsdim = default_obsdim(data)) = getobs(data, idx, obsdim)
 
 # --------------------------------------------------------------------
 
@@ -94,95 +95,14 @@ function targets end
 
 # --------------------------------------------------------------------
 
-"""
-    abstract DataView{TElem, TData} <: AbstractVector{TElem}
-
-Baseclass for all vector-like views of some data structure.
-This allow for example to see some design matrix as a vector of
-individual observation-vectors instead of one matrix.
-
-see `MLDataPattern.ObsView` and `MLDataPattern.BatchView` for examples.
-"""
-abstract type DataView{TElem, TData} <: AbstractVector{TElem} end
-
-"""
-    abstract AbstractObsView{TElem, TData} <: DataView{TElem, TData}
-
-Baseclass for all vector-like views of some data structure,
-that views it as some form or vector of observations.
-
-see `MLDataPattern.ObsView` for a concrete example.
-"""
-abstract type AbstractObsView{TElem, TData} <: DataView{TElem, TData} end
-
-"""
-    abstract AbstractBatchView{TElem, TData} <: DataView{TElem, TData}
-
-Baseclass for all vector-like views of some data structure,
-that views it as some form or vector of equally sized batches.
-
-see `MLDataPattern.BatchView` for a concrete example.
-"""
-abstract type AbstractBatchView{TElem, TData} <: DataView{TElem, TData} end
-
-# --------------------------------------------------------------------
-
-"""
-    abstract DataIterator{TElem,TData}
-
-Baseclass for all types that iterate over a `data` source
-in some manner. The total number of observations may or may
-not be known or defined and in general there is no contract that
-`getobs` or `nobs` has to be supported by the type of `data`.
-Furthermore, `length` should be used to query how many elements
-the iterator can provide, while `nobs` may return the underlying
-true amount of observations available (if known).
-
-see `MLDataPattern.RandomObs`, `MLDataPattern.RandomBatches`
-"""
-abstract type DataIterator{TElem,TData} end
-
-"""
-    abstract ObsIterator{TElem,TData} <: DataIterator{TElem,TData}
-
-Baseclass for all types that iterate over some data source
-one observation at a time.
-
-```julia
-using MLDataPattern
-@assert typeof(RandomObs(X)) <: ObsIterator
-
-for x in RandomObs(X)
-    # ...
-end
-```
+abstract type AbstractDataContainer end
 
-see `MLDataPattern.RandomObs`
-"""
-abstract type ObsIterator{TElem,TData} <: DataIterator{TElem,TData} end
-
-"""
-    abstract BatchIterator{TElem,TData} <: DataIterator{TElem,TData}
-
-Baseclass for all types that iterate over of some data source one
-batch at a time.
-
-```julia
-@assert typeof(RandomBatches(X, size=10)) <: BatchIterator
-
-for x in RandomBatches(X, size=10)
-    @assert nobs(x) == 10
-    # ...
-end
-```
-
-see `MLDataPattern.RandomBatches`
-"""
-abstract type BatchIterator{TElem,TData} <: DataIterator{TElem,TData} end
+Base.getindex(x::AbstractDataContainer, i) = getobs(x, i, default_obsdim(x))
+Base.iterate(x::AbstractDataContainer, state = 1) = getobs(x, state, default_obsdim(x)), state + 1
 
 # --------------------------------------------------------------------
 
-# just for dispatch for those who care to
-const AbstractDataIterator{E,T}  = Union{DataIterator{E,T}, DataView{E,T}}
-const AbstractObsIterator{E,T}   = Union{ObsIterator{E,T},  AbstractObsView{E,T}}
-const AbstractBatchIterator{E,T} = Union{BatchIterator{E,T},AbstractBatchView{E,T}}
+# Might need this distinction later
+# e.g. shuffleobs can be anywhere in pipeline but
+#      eachbatch is usually at the end
+abstract type AbstractDataIterator <: AbstractDataContainer end

test/observation.jl

@@ -13,9 +13,9 @@ using LearnBase: getobs, nobs, default_obsdim
         @test @inferred getobs(a, 1) == a[:,1]
         @test @inferred getobs(a, 2) == a[:,2]
         @test @inferred getobs(a, 1:2) == a[:,1:2]
-        @test @inferred getobs(a, 1, obsdim=1) == a[1,:]
-        @test @inferred getobs(a, 2, obsdim=1) == a[2,:]
-        @test @inferred getobs(a, 2, obsdim=nothing) ≈ a[:,2]
+        @test @inferred getobs(a, 1, 1) == a[1,:]
+        @test @inferred getobs(a, 2, 1) == a[2,:]
+        @test @inferred getobs(a, 2, nothing) ≈ a[:,2]
     end
 
     @testset "tuple" begin
@@ -36,7 +36,7 @@ using LearnBase: getobs, nobs, default_obsdim
         else
             o = getobs(dataset, 1:2)
         end
-        
+
         @test o[1] == X[:,1:2]
         @test o[2] == Y[1:2]
     end
@@ -53,7 +53,7 @@ using LearnBase: getobs, nobs, default_obsdim
         end
         @test o.x == X[:,2]
         @test o.y == Y[2]
-        
+
         if VERSION >= v"1.6"
             o = @inferred getobs(dataset, 1:2)
         else
@@ -67,7 +67,7 @@ using LearnBase: getobs, nobs, default_obsdim
         X, Y = rand(2, 3), rand(3)
         dataset = Dict("X" => X, "Y" => Y) 
         @test nobs(dataset) == 3
-        
+
         # o = @inferred getobs(dataset, 2) # not inferred
         o = getobs(dataset, 2)
         @test o["X"] == X[:,2]
@@ -78,5 +78,3 @@ using LearnBase: getobs, nobs, default_obsdim
         @test o["Y"] == Y[1:2]
     end
 end
-
-