anchor.diff:                   :max-depth max-depth :min-region-samples min-region-samples
                    :n-trial n-trial
                    :gain-test gain-test
  +                 :remove-sample-indices? remove-sample-indices?
                    :tmp-arr1 (make-array len :element-type 'fixnum :initial-element 0)
                    :tmp-index1 0
                    :tmp-arr2 (make-array len :element-type 'fixnum :initial-element 0)
  
positive.code:           (make-partial-arr (dtree-best-arr1 dtree) (dtree-best-index1 dtree))
            (node-sample-indices right-node)
            (make-partial-arr (dtree-best-arr2 dtree) (dtree-best-index2 dtree)))
      node))
  
  (defun stop-split? (node)
  
negative.code: 
  (defun make-forest (n-class datum-dim datamatrix target
                      &key (n-tree 100) (bagging-ratio 0.1) (max-depth 5) (min-region-samples 1)
                        (n-trial 10) (gain-test #'entropy) (remove-sample-indices? t))
    (let ((forest (%make-forest
                   :n-tree n-tree
                   :bagging-ratio bagging-ratio
  