feat(demo): majority function

SDeMo/src/ensembles/bagging.jl

@@ -57,7 +57,7 @@ is a simple majority rule.
 
 The additional keywords arguments are passed to `predict`.
 """
-function outofbag(ensemble::Bagging; thr::Float64=0.5, kwargs...)
+function outofbag(ensemble::Bagging; kwargs...)
     done_instances = Int64[]
     outcomes = Bool[]
 
@@ -70,9 +70,14 @@ function outofbag(ensemble::Bagging; thr::Float64=0.5, kwargs...)
                 for
                 i in valid_models
             ]
-            push!(outcomes, count(pred) > count(pred) // 2)
+            push!(outcomes, majority(pred))
         end
     end
 
-    return ConfusionMatrix(outcomes, ensemble.model.y[done_instances], thr)
+    return ConfusionMatrix(outcomes, ensemble.model.y[done_instances])
 end
+
+
+majority(pred::Vector{Bool}) = sum(pred) > length(pred) // 2
+majority(pred::BitVector) = sum(pred) > length(pred) // 2
+export majority