Add LabeledTable

Author: juliohm

src/StatsLearnModels.jl

@@ -22,13 +22,18 @@ import GLM
 import DecisionTree as DT
 import NearestNeighbors as NN
 
+include("labeledtable.jl")
 include("interface.jl")
 include("models/nn.jl")
 include("models/glm.jl")
 include("models/tree.jl")
 include("learn.jl")
 
 export
+  # labeled table
+  LabeledTable,
+  label,
+
   # NearestNeighbors.jl
   KNNClassifier,
   KNNRegressor,

src/labeledtable.jl

@@ -0,0 +1,31 @@
+# ------------------------------------------------------------------
+# Licensed under the MIT License. See LICENSE in the project root.
+# ------------------------------------------------------------------
+
+"""
+    LabeledTable(table, names)
+
+Stores a Tables.jl `table` along with column `names` that
+identify which columns are labels for supervised learning.
+"""
+struct LabeledTable{T}
+  table::T
+  labels::Vector{Symbol}
+end
+
+function LabeledTable(table, names)
+  Tables.istable(table) || throw(ArgumentError("please provide a valid Tables.jl table"))
+  cols = Tables.columns(table)
+  vars = Tables.columnnames(cols)
+  labs = selector(names)(vars)
+  labs ⊆ vars || throw(ArgumentError("all labels must be column names in the table"))
+  vars ⊆ labs && throw(ArgumentError("there must be at least one feature column in the table"))
+  LabeledTable{typeof(table)}(table, labs)
+end
+
+"""
+    label(table, names)
+
+Creates a `LabeledTable` from `table` using `names` as label columns.
+"""
+label(table, names) = LabeledTable(table, names)