def makeDecisionTree(data, attributes, default, target_attribute, iteration, numeric_attrs): iteration += 1 if iteration > 10: return Leaf(default) if not data: tree = Leaf(default) elif one_class(data): tree = Leaf(data[0][-1]) else: best_attr = selectAttr(data, attributes, target_attribute, numeric_attrs) if best_attr is False: tree = Leaf(default) else: split_examples = makeSplit(data, best_attr[0], best_attr[1], numeric_attrs) #new decision tree with root test *best_attr* best_attr.append(split_examples['numeric']) best_attr.append(attributes[best_attr[0]]) best_attr.append(split_examples["mode"]) tree = MiddleNode(best_attr) for branch_lab, branch_examples in split_examples['branches'].iteritems(): if not branch_examples: break sub_default = mode(branch_examples, -1) subtree = makeDecisionTree(branch_examples, attributes, sub_default, target_attribute, iteration, numeric_attrs) tree.add_branch(branch_lab, subtree, sub_default) return tree
def neighbor_joining(m, ids=None):
"""Neighbor Joining algorithm.
Given a distance matrix, the algorithm seeks a tree that approximates the
measured distances by greedily choosing to join the pair of elements that
minimize the total sum of edge lengths.
"""
n = len(m)
if ids is None:
ids = artificial_ids(n)
# Turn m symmetric (and floating-point) if it's not already
m = [[(m[i][j] + m[j][i]) / 2.0 for i in xrange(n)] for j in xrange(n)]
tree = [Leaf(id_) for id_ in ids]
for _ in xrange(n, 2, -1):
# Find closest neighbors
s = map(sum, m)
q = calculate_q(m, s)
# Join neighbors and update distance matrix
i, j = sorted(matrix_argmin(q))
m, di, dj = update_distance_matrix(m, s, i, j)
tree = join_neighbors(tree, i, j, di, dj)
d = m[0][1]
return join_neighbors(tree, 0, 1, d / 2, d / 2)[0]
def build_tree(dataset, attr_names):
"""
Recursively build the tree in the top to down manner.
Looks for the best split attribute on current node.
If the reduction on impurity after split is 0, then return a Leaf node.
Otherwise split using the best condition calculated.
Call build_tree on its left child and then on its right child.
:param dataset: a 2d list representing a list of data objects :param attr_names: a list containing attribute
names
:return: a node with left child as left_branch and right child as right_branch and condition as the best
splitting condition on this node.
"""
condition, imp_red = best_split(dataset, attr_names)
if imp_red == 0:
return Leaf(dataset)
left_rows, right_rows = split_on_condition(dataset, condition)
left_branch = build_tree(left_rows, attr_names)
right_branch = build_tree(right_rows, attr_names)
return Node(condition, left_branch, right_branch)
def shunting_yard_AST(tokens: Iterable[str]) -> Tree:
"""
Takes a list of tokens and produces a Tree of operators with the query terms at the Leaf
*Description of the algorithm*:
1. read token
- if operands => queue
- if not op. o1 take o2 from op stack while op1 <= op2 and put o2 in out, then put o1 in stack
- if ( put it on stack
- if ) empty the stack in the queue until you find a ( (or error)
2. when no more token
- if still some tokens (but parenthesis => error) => queue
"""
if len(tokens) == 0: # Support empty query
return Leaf('__Empty__')
output = []
stack = []
for token in tokens:
if token not in OPERATORS:
output.append(Leaf(token))
elif token == '(':
stack.append(token)
elif token == ')':
pop = ''
while len(stack) != 0 and pop != '(':
pop = stack.pop()
if pop != '(':
add_node(output, pop)
if pop != '(':
raise Exception("Mismatching parenthesis", pop, stack)
else:
while len(stack) != 0:
pop = stack.pop()
if OPERATORS[token] <= OPERATORS[pop]:
add_node(output, pop)
else:
stack.append(pop)
break
stack.append(token)
while len(stack) > 0:
if stack[-1] in "()":
raise Exception("Unexpected ( )")
else:
add_node(output, stack.pop())
return output.pop()
def _random_joining(ids):
"""Generates a tree by repeatedly joining elements randomly."""
r = Random()
tree = [Leaf(id_) for id_ in ids]
for _ in xrange(len(ids) - 1):
i, j = sorted(r.sample(xrange(len(tree)), 2))
tree = join_neighbors(tree, i, j, r.random(), r.random())
return tree[0]
def expand(start, end, tag):
"""Yield all trees rooted by tag over words[start:end]."""
if end - start == 1:
word = words[start]
if tag in tags_for_word(word):
yield Leaf(tag, word)
if tag in grammar:
for tags in grammar[tag]:
for branches in expand_all(start, end, tags):
yield Tree(tag, branches)
def id3(Y, D, U):
# zwrócenie liścia gdy jest jedna klasa
if _is_one_class(U):
if len(U) != 0:
return Leaf(U[0]['y'])
return Leaf(choice(Y))
# zwrócenie liścia gdy nie ma decyzji do rozpatrzenia
if len(D) == 0:
return Leaf(_most_common_class(U))
# wybranie decyzji dla której entropia zbiorów jest największa
d = max(D, key=lambda d: _Inf_gain(d, U))
U = _divide_set(d, U)
D.remove(d)
# zwrócenie korzenia drzewa z pozostałymi decyzjami
return Node(
d,
[Edge(d['values'][i], id3(Y, D, U[i])) for i in range(len(U))]
)
def create_leaf(tree, label, tag=None):
"""
A function that creates a leaf from a tree in a string format.
:param tree: the tree in a string format.
:param label: the sentiment label of this leaf (if exists).
:param tag: the constituent tag of this leaf.
:return: the leaf created according to the word and labels.
"""
global counter
word = find_word(tree)
leaf = Leaf(label, word, tag)
counter += 1
return leaf
def read_tree(tokens):
"""Read the next well-formed tree, removing empty constituents."""
tag = next(tokens).split('-')[0].split('=')[0].split('|')[0]
element = next(tokens)
if element != '(':
assert next(tokens) == ')'
return Leaf(tag, element)
branches = []
while element != ')':
assert element == '('
branch = read_tree(tokens)
if branch and branch.tag:
branches.append(branch)
element = next(tokens)
if branches:
return Tree(tag, branches)
def test_append(self):
# Action, get tree.
t = self.t
# Action, append leaf in the root of tree.
leaf = Leaf({'name': 'test leaf'})
t.append(leaf)
# Asert, leaf == last item, in the root of the tree.
self.assertEqual(leaf, t[-1])
# Action, append leaf in the root of a subtree.
subtree = t.query('Node Four')
subtree.append(leaf)
# Asert, leaf == last item, in the root of the subtree.
self.assertEqual(leaf, subtree[-1])
def test_set_cell(self):
# Action, get tree.
t = self.t
# Action, insert leaf in the root of tree.
leaf = Leaf({'name': 'test leaf', 'columns': ['test1', 'test2', 'test3']})
t.append(leaf)
# Asert, leaf was appended.
self.assertEqual(leaf.name, t.query('test leaf').name)
# Asert, column value == 'test1'
self.assertEqual('test1', t.get_cell(leaf.id, 1))
self.assertEqual('test1', t.get_cell('test leaf', 1))
# Action, set column value.
t.set_cell('test leaf', 2, 'TEST2')
# Asert, column value == 'TWO' (upper case)
self.assertEqual('TEST2', t.get_cell('test leaf', 2))
def add_leaf(self, tree, spot_info):
"""Add a falling leaf."""
fall_time = randint(2000, 2500)
leaf = Leaf(tree, spot_info, self.leaves, self.all_sprites)
y = leaf.rect.centery + leaf.fall_distance
ani = Animation(centery=y, duration=fall_time, round_values=True)
ani.callback = leaf.land
ani.start(leaf.rect)
ani2 = Animation(centery=leaf.collider.centery + leaf.fall_distance,
duration=fall_time,
round_values=True)
ani2.start(leaf.collider)
fade = Animation(img_alpha=0,
duration=3000,
delay=fall_time,
round_values=True)
fade.callback = leaf.kill
fade.update_callback = leaf.set_alpha
fade.start(leaf)
self.animations.add(ani, ani2, fade)
def test_insert(self):
# Action, get tree.
t = deepcopy(self.t)
t = self.t
# Action, set item counter to 0.
t.items = 0
# Action, create leafs.
leaf1 = Leaf({'name': 'test leaf1'})
leaf2 = Leaf({'name': 'test leaf2'})
leaf3 = Leaf({'name': 'test leaf3'})
# Action, insert leafs.
t.insert(0, leaf1)
t.insert(2, leaf2)
t.insert(len(t), leaf3)
# Asert, leaf == item inserted at index.
self.assertEqual(leaf1, t[0])
self.assertEqual(leaf2, t[2])
self.assertEqual(leaf3, t[len(t)-1])
# Action, create leafs.
leaf1 = Leaf({'name': 'test leaf1'})
leaf2 = Leaf({'name': 'test leaf2'})
leaf3 = Leaf({'name': 'test leaf3'})
# Action, get node.
t = deepcopy(self.t)
subtree = t.query('Node Three')
# Action, insert leafs.
subtree.insert(0, leaf1)
subtree.insert(2, leaf2)
subtree.insert(len(subtree), leaf3)
# Asert, leaf == item inserted at index.
self.assertEqual(subtree, t.query('Node Three'))
self.assertEqual(leaf1, subtree[0])
self.assertEqual(leaf2, subtree[2])
self.assertEqual(leaf3, subtree[len(subtree)-1])
def nja(matrix):
#Compute all unique keys in the matrix
keys = set()
for pair in matrix.keys():
for elem in pair:
keys.add(elem)
#For all keys i, caluclate its r(i) according to step 1 of the NJA
keysum = dict()
for i in keys:
total = sum([v for (a, b), v in matrix.items() if i == a])
keysum[i] = total
#For a given pair i,j calculate the value given by step 2 of the NJA
def Q(i, j):
m = matrix[(i, j)]
sumi = keysum[i]
sumj = keysum[j]
return m - ((sumi + sumj) / len(keysum) - 2)
#Compute a dictionary which contains value of the formula given by step 2 for
#all possible i,j pairs
Qmatrix = dict()
for i, j in itertools.permutations(keys, 2):
Qmatrix[(i, j)] = Q(i, j)
#Find the minimum i,j pair by sorting the dictionary by its values
minpair = sorted(Qmatrix.items(), key=lambda x: x[1])[0][0]
i, j = minpair
#Create a new node for the PT, with i and j as leaves
inode = Leaf(str(i))
jnode = Leaf(str(j))
node = Node(inode, jnode)
#Calculate the distance to i and j from the new node.
def Q1(i, j, right=False):
m = matrix[(i, j)]
sumi = keysum[i]
sumj = keysum[j]
if right:
return (m + ((sumj - sumi) / len(keysum) - 2.0)) / 2
else:
return (m + ((sumi - sumj) / len(keysum) - 2.0)) / 2
#Add the distances to the node object,
node.dleft = Q1(i, j)
node.dright = Q1(i, j, True)
#Calculate the distances from all other nodes to the new node and add them to the
#matrix
matrix[(minpair, minpair)] = 0
for k in keys:
if k != i or k != j:
ij = matrix[(i, j)]
ik = matrix[(i, k)]
jk = matrix[(j, k)]
matrix[(minpair, k)] = (ik + jk - ij) / 2
matrix[(k, minpair)] = (ik + jk - ij) / 2
#Delete all values from the old i and j keys from the matrix
todel = [pair for pair in matrix.keys() if i in pair or j in pair]
for key in todel:
del matrix[key]
return node
from tree import Tree, Leaf
from print_tree import print_tree
lexicon = {
Leaf('N', 'buffalo'), # bison
Leaf('V', 'buffalo'), # intimidate
Leaf('J', 'buffalo'), # New York
Leaf('R', 'that'),
}
grammar = {
'S': [['NP', 'VP']],
'NP': [['N'], ['J', 'N'], ['NP', 'RP']],
'VP': [['V', 'NP']],
'RP': [['R', 'NP', 'V'], ['NP', 'V']],
}
def expand(tag):
"""Yield all trees rooted by tag."""
for leaf in lexicon:
if leaf.tag == tag:
yield leaf
if tag in grammar:
for tags in grammar[tag]:
for branches in expand_all(tags):
yield Tree(tag, branches)
def expand_all(tags):
"""Yield all sequences of branches for a sequence of tags."""
from tree import Tree, Leaf
from print_tree import print_tree
lexicon = {
Leaf('N', 'buffalo'), # beasts
Leaf('V', 'buffalo'), # intimidate
}
grammar = {
'S': [['NP', 'VP']],
'NP': [['N']],
'VP': [['V', 'NP']],
}
def expand(tag):
"""Yield all trees rooted by tag."""
def expand_all(tags):
"""Yield all sequences of branches for a sequence of tags."""
#!/usr/bin/python3
from pretty_printer import PreOrderVisitor, InOrderVisitor, LeavesVisitor
from tree import Node, Leaf
myTree = Node(Leaf(1), Node(Node(Leaf(3), Leaf(5), 4), Leaf(7), 6), 2)
def main():
pp = PreOrderVisitor()
myTree.accept(pp)
print("----------")
pp = InOrderVisitor()
myTree.accept(pp)
print("----------")
pp = LeavesVisitor()
myTree.accept(pp)
if __name__ == "__main__":
main()
from tree import Tree, Leaf
from print_tree import print_tree
lexicon = {
Leaf('N', 'buffalo'), # beasts
Leaf('V', 'buffalo'), # intimidate
Leaf('J', 'buffalo'), # from New York
Leaf('R', 'that')
}
grammar = {
'S': [['NP', 'VP']],
'NP': [['N'], ['J', 'N'], ['NP', 'RP']],
'VP': [['V', 'NP']],
'RP': [['R', 'NP', 'V']],
}
def expand(tag):
"""Yield all trees rooted by tag."""
for leaf in lexicon:
if tag == leaf.tag:
yield leaf
if tag in grammar:
for tags in grammar[tag]:
for branches in expand_all(tags):
yield Tree(tag, branches)
def expand_all(tags):
"""Yield all sequences of branches for a sequence of tags."""
