Process outputs for Multiclass Classification.

processOutputMulti.hs

import qualified Data.Vector.Storable as V
import qualified Numeric.LinearAlgebra as LA

-- | Process outputs for Multiclass Classification.
-- Takes number of labels and output vector y.
-- Returns matrix of binary outputs (One-vs-All Classification).
-- It is supposed that labels are integerets start at 0.

processOutputMulti :: Int -> Vector -> Matrix
processOutputMulti numLabels y = LA.fromColumns $ map f [0 .. numLabels-1]
  where f sample = V.map (\a -> if round a == sample then 1 else 0) y


processOutputMulti numLabels y = LA.assoc (V.length y, numLabels) 0 assocList
  where assocList = zipWith (\index label -> ((index, round label), 1)) [0..] (V.toList y)