def create_pointer(self, attempts=100, unitary=False):
"""Create a new semantic pointer.
This will take into account the randomize and max_similarity
parameters from self.
"""
if self.randomize:
count = 0
p = pointer.SemanticPointer(self.dimensions, rng=self.rng)
if self.vectors.shape[0] > 0:
while count < 100:
similarity = np.dot(self.vectors, p.v)
if max(similarity) < self.max_similarity:
break
p = pointer.SemanticPointer(self.dimensions, rng=self.rng)
count += 1
else:
warnings.warn('Could not create a semantic pointer with '
'max_similarity=%1.2f (D=%d, M=%d)' %
(self.max_similarity, self.dimensions,
len(self.pointers)))
# Check and make vector unitary if needed
if unitary:
p.make_unitary()
else:
index = len(self.pointers)
if index >= self.dimensions:
raise IndexError('Tried to make more semantic pointers than' +
' dimensions with non-randomized Vocabulary')
p = pointer.SemanticPointer(np.eye(self.dimensions)[index])
return p
def identity(self):
"""Return the identity vector."""
if self._identity is None:
v = np.zeros(self.dimensions)
v[0] = 1
self._identity = pointer.SemanticPointer(v)
return self._identity
def add(self, key, p):
"""Add a new semantic pointer to the vocabulary.
The pointer value can be a `.SemanticPointer` or a vector.
"""
if self.readonly:
raise ReadonlyError(attr='Vocabulary',
msg="Cannot add semantic pointer '%s' to "
"read-only vocabulary." % key)
if not key[0].isupper():
raise SpaParseError(
"Semantic pointers must begin with a capital letter.")
if not isinstance(p, pointer.SemanticPointer):
p = pointer.SemanticPointer(p)
if key in self.pointers:
raise ValidationError("The semantic pointer %r already exists"
% key, attr='pointers', obj=self)
self.pointers[key] = p
self.keys.append(key)
self.vectors = np.vstack([self.vectors, p.v])
# Generate vector pairs
if self.include_pairs and len(self.keys) > 1:
for k in self.keys[:-1]:
self.key_pairs.append('%s*%s' % (k, key))
v = (self.pointers[k] * p).v
self.vector_pairs = np.vstack([self.vector_pairs, v])
def create_pointer(self, attempts=100, unitary=False):
"""Create a new semantic pointer.
This will take into account the randomize and max_similarity
parameters from self. If a pointer satisfying max_similarity
is not generated after the specified number of attempts, the
candidate pointer with lowest maximum cosine with all existing
pointers is returned.
"""
if self.randomize:
if self.vectors.shape[0] == 0:
p = pointer.SemanticPointer(self.dimensions, rng=self.rng)
else:
p_sim = np.inf
for _ in range(attempts):
pp = pointer.SemanticPointer(self.dimensions, rng=self.rng)
pp_sim = max(np.dot(self.vectors, pp.v))
if pp_sim < p_sim:
p = pp
p_sim = pp_sim
if p_sim < self.max_similarity:
break
else:
warnings.warn(
'Could not create a semantic pointer with '
'max_similarity=%1.2f (D=%d, M=%d)'
% (self.max_similarity,
self.dimensions,
len(self.pointers)))
# Check and make vector unitary if needed
if unitary:
p.make_unitary()
else:
index = len(self.pointers)
if index >= self.dimensions:
raise ValidationError(
"Tried to make more semantic pointers than "
"dimensions with non-randomized Vocabulary",
attr='dimensions', obj=self)
p = pointer.SemanticPointer(np.eye(self.dimensions)[index])
return p
def add(self, key, p):
"""Add a new semantic pointer to the vocabulary.
The pointer value can be a SemanticPointer or a vector.
"""
if not key[0].isupper():
raise KeyError('Semantic pointers must begin with a capital')
if not isinstance(p, pointer.SemanticPointer):
p = pointer.SemanticPointer(p)
if key in self.pointers:
raise KeyError("The semantic pointer '%s' already exists" % key)
self.pointers[key] = p
self.keys.append(key)
self.vectors = np.vstack([self.vectors, p.v])
# Generate vector pairs
if self.include_pairs and len(self.keys) > 1:
for k in self.keys[:-1]:
self.key_pairs.append('%s*%s' % (k, key))
v = (self.pointers[k] * p).v
self.vector_pairs = np.vstack([self.vector_pairs, v])
