def unfolded_decoding(W_d, b_d, tree, encoded):
(n, m) = W_d.shape
# store all a_e results in tree structure
decoding_tree = Tree(encoded, [])
try:
decoding_tree.span = tree.span
except:
pass
# if the given node (root) has children, decode the node's encoding, split it,
# and use this as the children's encoding (output) to recurse back, until terminal
# nodes are reached
if type(tree) == nltk.tree.Tree and len(tree) > 0:
decoded = decode(W_d, b_d, encoded)
for i, child in enumerate(tree):
# NOTE: the number of branchings n is NOT assumed, but that it is uniform and that
# len(input layer) = n*len(encoding) IS assumed
full_decoded = unfolded_decoding(W_d, b_d, child, decoded[i * m : m + (i * m)])
decoding_tree.append(full_decoded)
return decoding_tree
else:
decoding_tree = Tree(encoded, [])
try:
decoding_tree.span = tree.span
except:
pass
return decoding_tree
def init_tree(tree, bf, cn=0):
# if it is a tree, might not be non terminal...
if type(tree) == nltk.tree.Tree:
# check for correct branching factor
if len(tree) == bf:
# check for errors (False return) and recurse up to discard entire tree
children = []
for i, t in enumerate(tree):
initialized_tree = init_tree(t, bf, cn * bf + i)
if initialized_tree is not False:
children.append(initialized_tree)
else:
return False
out = Tree(tree.node, children)
out.span = (out[0].span[0], out[-1].span[1])
# if tree & len = 0, is a terminal node (if not NoneType node)
elif len(tree) == 0:
out = Tree(tree.node, [])
try:
out.span = (cn * len(out.node), (cn + 1) * len(out.node) - 1)
except TypeError:
print "non-terminal ERROR: NoneType node encountered, tree discarded from training set."
return False
# if not a terminal node or of correct branching factor, discard
else:
print "non-terminal ERROR: wrong branching factor, tree discarded from training set."
return False
# if it is not a tree and not None, assume it is a terminal node array, wrap in tree
elif tree is not None:
out = Tree(tree, [])
out.span = ((cn - 1) * len(out.node), cn * len(out.node) - 1)
# if None though, discard
else:
print "non-terminal ERROR: terminal node " + str(cn) + " is NoneType, tree discarded from training set."
return False
out.cn = cn
return out
