distance to tree with different branching biases

build_tree.py

#balanced tree construction
def build_tree(depth, sen):
    assert len(depth) == len(sen)
    assert len(depth) >= 0

    if len(depth) == 1:
        parse_tree = sen[0]
    else:
        idx_max = numpy.argmax(depth[1:]) + 1
        parse_tree = []
        if len(sen[:idx_max]) > 0:
            tree0 = build_tree(depth[:idx_max], sen[:idx_max])
            parse_tree.append(tree0)
        if len(sen[idx_max:]) > 0:
            tree1 = build_tree(depth[idx_max:], sen[idx_max:])
            parse_tree.append(tree1)
    return parse_tree

  # with right branching bias
  def build_tree(depth, sen):
    assert len(depth) == len(sen)

    if len(depth) == 1:
        parse_tree = sen[0]
    else:
        idx_max = numpy.argmax(depth)
        parse_tree = []
        tree_head = sen[idx_max]
        if len(sen[:idx_max]) > 0:
            tree0 = build_tree(depth[:idx_max], sen[:idx_max])
            parse_tree.append(tree0)

        if len(sen[idx_max + 1:]) > 0:
            tree1 = build_tree(depth[idx_max + 1:], sen[idx_max + 1:])
            tree_head = [tree_head, tree1]
            
        if parse_tree == []:
            parse_tree = tree_head
        else:
            parse_tree.append(tree_head)
    return parse_tree
  
  # with left branching bias
  def build_tree(depth, sen):
    assert len(depth) == len(sen)

    if len(depth) == 1:
        parse_tree = sen[0]
    else:
        idx_max = numpy.argmax(depth)
        parse_tree = []
        tree_head = sen[idx_max]
        if len(sen[:idx_max]) > 0:
            tree0 = build_tree(depth[:idx_max], sen[:idx_max])
            tree_head = [tree0, tree_head]
            parse_tree.append(tree_head)
            
        if len(sen[idx_max + 1:]) > 0:
            tree1 = build_tree(depth[idx_max + 1:], sen[idx_max + 1:])
            parse_tree.append(tree1)
            
        if parse_tree == []:
            parse_tree = tree_head
    return parse_tree