def validate(self, instance, ndarray):
ndim = len(self.shape)
try:
ndarray = np.asarray(ndarray, dtype=np.float64)
except TypeError:
raise ValueError("Must be a float NumPy array (got type '%s')"
% ndarray.__class__.__name__)
if ndarray.ndim != ndim:
raise ValueError("ndarray must be %dD (got %dD)"
% (ndim, ndarray.ndim))
for i, attr in enumerate(self.shape):
assert is_integer(attr) or is_string(attr), (
"shape can only be an int or str representing an attribute")
if attr == '*':
continue
if is_integer(attr):
desired = attr
elif is_string(attr):
desired = getattr(instance, attr)
if ndarray.shape[i] != desired:
raise ValueError("shape[%d] should be %d (got %d)"
% (i, desired, ndarray.shape[i]))
return ndarray
def validate(self, instance, ndarray):
ndim = len(self.shape)
try:
ndarray = np.asarray(ndarray, dtype=np.float64)
except TypeError:
raise ValueError("Must be a float NumPy array (got type '%s')" %
ndarray.__class__.__name__)
if ndarray.ndim != ndim:
raise ValueError("ndarray must be %dD (got %dD)" %
(ndim, ndarray.ndim))
for i, attr in enumerate(self.shape):
assert is_integer(attr) or is_string(attr), (
"shape can only be an int or str representing an attribute")
if attr == '*':
continue
if is_integer(attr):
desired = attr
elif is_string(attr):
desired = getattr(instance, attr)
if ndarray.shape[i] != desired:
raise ValueError("shape[%d] should be %d (got %d)" %
(i, desired, ndarray.shape[i]))
return ndarray
def validate(self, instance, ndarray):
ndim = len(self.shape)
try:
ndarray = np.asarray(ndarray, dtype=np.float64)
except TypeError:
raise ValueError("Must be a float NumPy array (got type '%s')"
% ndarray.__class__.__name__)
if ndarray.ndim != ndim:
raise ValueError("ndarray must be %dD (got %dD)"
% (ndim, ndarray.ndim))
for i, attr in enumerate(self.shape):
assert is_integer(attr) or is_string(attr), (
"shape can only be an int or str representing an attribute")
if attr == '*':
continue
desired = attr if is_integer(attr) else getattr(instance, attr)
if not is_integer(desired):
raise ValueError("%s not yet initialized; cannot determine "
"if shape is correct. Consider using a "
"distribution instead." % attr)
if ndarray.shape[i] != desired:
raise ValueError("shape[%d] should be %d (got %d)"
% (i, desired, ndarray.shape[i]))
return ndarray
def validate(self, instance, ndarray):
ndim = len(self.shape)
try:
ndarray = np.asarray(ndarray, dtype=np.float64)
except TypeError:
raise ValueError("Must be a float NumPy array (got type '%s')" %
ndarray.__class__.__name__)
if ndarray.ndim != ndim:
raise ValueError("ndarray must be %dD (got %dD)" %
(ndim, ndarray.ndim))
for i, attr in enumerate(self.shape):
assert is_integer(attr) or is_string(attr), (
"shape can only be an int or str representing an attribute")
if attr == '*':
continue
desired = attr if is_integer(attr) else getattr(instance, attr)
if not is_integer(desired):
raise ValueError("%s not yet initialized; cannot determine "
"if shape is correct. Consider using a "
"distribution instead." % attr)
if ndarray.shape[i] != desired:
raise ValueError("shape[%d] should be %d (got %d)" %
(i, desired, ndarray.shape[i]))
return ndarray
def coerce_ndarray(self, instance, ndarray): # noqa: C901
if isinstance(ndarray, np.ndarray):
ndarray = ndarray.view()
else:
try:
ndarray = np.array(ndarray, dtype=np.float64)
except (ValueError, TypeError):
raise ValidationError(
"Must be a float NumPy array (got type %r)"
% type(ndarray).__name__, attr=self.name, obj=instance)
if self.readonly:
ndarray.setflags(write=False)
if self.shape is None:
return ndarray
if '...' in self.shape:
# Convert '...' to the appropriate number of '*'s
nfixed = len(self.shape) - 1
n = ndarray.ndim - nfixed
if n < 0:
raise ValidationError("ndarray must be at least %dD (got %dD)"
% (nfixed, ndarray.ndim),
attr=self.name, obj=instance)
i = self.shape.index('...')
shape = list(self.shape[:i]) + (['*'] * n)
if i < len(self.shape) - 1:
shape.extend(self.shape[i+1:])
else:
shape = self.shape
if ndarray.ndim != len(shape):
raise ValidationError("ndarray must be %dD (got %dD)"
% (len(shape), ndarray.ndim),
attr=self.name, obj=instance)
for i, attr in enumerate(shape):
assert is_integer(attr) or is_string(attr), (
"shape can only be an int or str representing an attribute")
if attr == '*':
continue
desired = attr if is_integer(attr) else getattr(instance, attr)
if not is_integer(desired):
raise ValidationError(
"%s not yet initialized; cannot determine if shape is "
"correct. Consider using a distribution instead." % attr,
attr=self.name, obj=instance)
if ndarray.shape[i] != desired:
raise ValidationError("shape[%d] should be %d (got %d)"
% (i, desired, ndarray.shape[i]),
attr=self.name, obj=instance)
return ndarray
def validate(self, instance, ndarray): # noqa: C901
if isinstance(ndarray, np.ndarray):
ndarray = ndarray.view()
else:
try:
ndarray = np.array(ndarray, dtype=np.float64)
except (ValueError, TypeError):
raise ValidationError(
"Must be a float NumPy array (got type %r)" % ndarray.__class__.__name__,
attr=self.name,
obj=instance,
)
if self.readonly:
ndarray.setflags(write=False)
if "..." in self.shape:
# Convert '...' to the appropriate number of '*'s
nfixed = len(self.shape) - 1
n = ndarray.ndim - nfixed
if n < 0:
raise ValidationError(
"ndarray must be at least %dD (got %dD)" % (nfixed, ndarray.ndim), attr=self.name, obj=instance
)
i = self.shape.index("...")
shape = list(self.shape[:i]) + (["*"] * n)
if i < len(self.shape) - 1:
shape.extend(self.shape[i + 1 :])
else:
shape = self.shape
if ndarray.ndim != len(shape):
raise ValidationError(
"ndarray must be %dD (got %dD)" % (len(shape), ndarray.ndim), attr=self.name, obj=instance
)
for i, attr in enumerate(shape):
assert is_integer(attr) or is_string(attr), "shape can only be an int or str representing an attribute"
if attr == "*":
continue
desired = attr if is_integer(attr) else getattr(instance, attr)
if not is_integer(desired):
raise ValidationError(
"%s not yet initialized; cannot determine if shape is "
"correct. Consider using a distribution instead." % attr,
attr=self.name,
obj=instance,
)
if ndarray.shape[i] != desired:
raise ValidationError(
"shape[%d] should be %d (got %d)" % (i, desired, ndarray.shape[i]), attr=self.name, obj=instance
)
return ndarray
def validate(self, instance, ndarray): # noqa: C901
if isinstance(ndarray, np.ndarray):
ndarray = ndarray.view()
else:
try:
ndarray = np.array(ndarray, dtype=np.float64)
except TypeError:
raise ValueError(
"Must be a float NumPy array (got type '%s')" %
ndarray.__class__.__name__)
if self.readonly:
ndarray.setflags(write=False)
if '...' in self.shape:
nfixed = len(self.shape) - 1
n = ndarray.ndim - nfixed
if n < 0:
raise ValueError("ndarray must be at least %dD (got %dD)" %
(nfixed, ndarray.ndim))
i = self.shape.index('...')
shape = list(self.shape[:i]) + (['*'] * n)
if i < len(self.shape) - 1:
shape.extend(self.shape[i + 1:])
else:
shape = self.shape
if ndarray.ndim != len(shape):
raise ValueError("ndarray must be %dD (got %dD)" %
(len(shape), ndarray.ndim))
for i, attr in enumerate(shape):
assert is_integer(attr) or is_string(attr), (
"shape can only be an int or str representing an attribute")
if attr == '*':
continue
desired = attr if is_integer(attr) else getattr(instance, attr)
if not is_integer(desired):
raise ValueError("%s not yet initialized; cannot determine "
"if shape is correct. Consider using a "
"distribution instead." % attr)
if ndarray.shape[i] != desired:
raise ValueError("shape[%d] should be %d (got %d)" %
(i, desired, ndarray.shape[i]))
return ndarray
def __init__(
self, dimensions, strict=True, max_similarity=0.1,
pointer_gen=None, name=None, algebra=None):
if algebra is None:
algebra = HrrAlgebra()
self.algebra = algebra
if not is_integer(dimensions) or dimensions < 1:
raise ValidationError("dimensions must be a positive integer",
attr='dimensions', obj=self)
if pointer_gen is None:
pointer_gen = UnitLengthVectors(dimensions)
elif isinstance(pointer_gen, np.random.RandomState):
pointer_gen = UnitLengthVectors(dimensions, pointer_gen)
if not is_iterable(pointer_gen) or is_string(pointer_gen):
raise ValidationError(
"pointer_gen must be iterable or RandomState",
attr='pointer_gen', obj=self)
self.dimensions = dimensions
self.strict = strict
self.max_similarity = max_similarity
self._key2idx = {}
self._keys = []
self._vectors = np.zeros((0, dimensions), dtype=float)
self.pointer_gen = pointer_gen
self.name = name
def __init__(self,
dimensions,
randomize=True,
unitary=False,
max_similarity=0.1,
include_pairs=False,
rng=None):
if not is_integer(dimensions) or dimensions < 1:
raise ValidationError("dimensions must be a positive integer",
attr='dimensions',
obj=self)
self.dimensions = dimensions
self.randomize = randomize
self.unitary = unitary
self.max_similarity = max_similarity
self.pointers = {}
self.keys = []
self.key_pairs = None
self.vectors = np.zeros((0, dimensions), dtype=float)
self.vector_pairs = None
self._include_pairs = None
self.include_pairs = include_pairs
self._identity = None
self.rng = rng
self.readonly = False
self.parent = None
def __init__(self, obj, key=slice(None)):
self.obj = obj
# Node.size_in != size_out, so one of these can be invalid
# NumPy <= 1.8 raises a ValueError instead of an IndexError.
try:
self.size_in = np.arange(self.obj.size_in)[key].size
except (IndexError, ValueError):
self.size_in = None
try:
self.size_out = np.arange(self.obj.size_out)[key].size
except (IndexError, ValueError):
self.size_out = None
if self.size_in is None and self.size_out is None:
raise IndexError("Invalid slice '%s' of %s" % (key, self.obj))
if is_integer(key):
# single slices of the form [i] should be cast into
# slice objects for convenience
if key == -1:
# special case because slice(-1, 0) gives the empty list
self.slice = slice(key, None)
else:
self.slice = slice(key, key + 1)
else:
self.slice = key
def __init__(self,
dimensions,
randomize=True,
unitary=False,
max_similarity=0.1,
include_pairs=False,
rng=None):
if not is_integer(dimensions):
raise TypeError('dimensions must be an integer')
if dimensions < 1:
raise ValueError('dimensions must be positive')
self.dimensions = dimensions
self.randomize = randomize
self.unitary = unitary
self.max_similarity = max_similarity
self.pointers = {}
self.keys = []
self.key_pairs = None
self.vectors = np.zeros((0, dimensions), dtype=float)
self.vector_pairs = None
self._include_pairs = None
self.include_pairs = include_pairs
self._identity = None
self.rng = rng
def __init__(
self, stim_provider, items, contexts, n_pos, rng=None,
extra_pos=3):
super(Vocabularies, self).__init__()
vocabs = Config.default(spa.Network, 'vocabs')
if vocabs is None:
vocabs = VocabularyMap(rng=rng)
self.vocabs = vocabs
self.items = items
if is_integer(contexts):
contexts = spa.Vocabulary(contexts, rng=rng)
self.contexts = contexts
self.positions = spa.Vocabulary(self.items.dimensions, rng=rng)
self.items.populate(';'.join(stim_provider.get_all_items()))
if stim_provider.n_distractors_per_epoch > 0:
self.items.populate(';'.join(stim_provider.get_all_distractors()))
for i in range(self.items.dimensions):
self.contexts.populate('CTX' + str(i))
for i in range(n_pos + extra_pos):
self.positions.populate('P' + str(i))
def __init__(self, obj, key=slice(None)):
self.obj = obj
if is_integer(key):
# single slices of the form [i] should be cast into
# slice objects for convenience
if key == -1:
# special case because slice(-1, 0) gives the empty list
key = slice(key, None)
else:
key = slice(key, key + 1)
self.slice = key
# Node.size_in != size_out, so one of these can be invalid
try:
self.size_in = np.arange(self.obj.size_in)[self.slice].size
except IndexError:
self.size_in = None
try:
self.size_out = np.arange(self.obj.size_out)[self.slice].size
except IndexError:
self.size_out = None
if self.size_in is None and self.size_out is None:
raise ValidationError("Invalid slice '%s' of %s" %
(self.slice, self.obj),
attr='key')
def validate(self, instance, ndarray): # noqa: C901
if isinstance(ndarray, np.ndarray):
ndarray = ndarray.view()
else:
try:
ndarray = np.array(ndarray, dtype=np.float64)
except TypeError:
raise ValueError("Must be a float NumPy array (got type '%s')"
% ndarray.__class__.__name__)
if self.readonly:
ndarray.setflags(write=False)
if '...' in self.shape:
nfixed = len(self.shape) - 1
n = ndarray.ndim - nfixed
if n < 0:
raise ValueError("ndarray must be at least %dD (got %dD)"
% (nfixed, ndarray.ndim))
i = self.shape.index('...')
shape = list(self.shape[:i]) + (['*'] * n)
if i < len(self.shape) - 1:
shape.extend(self.shape[i+1:])
else:
shape = self.shape
if ndarray.ndim != len(shape):
raise ValueError("ndarray must be %dD (got %dD)"
% (len(shape), ndarray.ndim))
for i, attr in enumerate(shape):
assert is_integer(attr) or is_string(attr), (
"shape can only be an int or str representing an attribute")
if attr == '*':
continue
desired = attr if is_integer(attr) else getattr(instance, attr)
if not is_integer(desired):
raise ValueError("%s not yet initialized; cannot determine "
"if shape is correct. Consider using a "
"distribution instead." % attr)
if ndarray.shape[i] != desired:
raise ValueError("shape[%d] should be %d (got %d)"
% (i, desired, ndarray.shape[i]))
return ndarray
def sample(self, n, d=1, rng=np.random):
"""Samples ``n`` points in ``d`` dimensions."""
if d == 1:
# Tile the points optimally. TODO: refactor
return np.linspace(1. / n, 1, n)[:, None]
if d is None or not is_integer(d) or d < 1:
# TODO: this should be raised when the ensemble is created
raise ValueError("d (%d) must be positive integer" % d)
return _rd_generate(n, d)
def validate(self, instance, value):
super(ShapeParam, self).validate(instance, value)
for i, v in enumerate(value):
if not is_integer(v):
raise ValidationError("Element %d must be an int (got type %r)"
% (i, type(v).__name__),
attr=self.name, obj=instance)
if self.low is not None and v < self.low:
raise ValidationError(
"Element %d must be >= %d (got %d)" % (i, self.low, v),
attr=self.name, obj=instance)
def __pow__(self, other):
if not is_integer(other):
return NotImplemented
n, d = self.tf
if other > 0:
return LinearSystem(normalize(n**other, d**other), self.analog)
elif other < 0:
return LinearSystem(normalize(d**-other, n**-other), self.analog)
else:
assert other == 0
return LinearSystem(1., self.analog)
def coerce(self, instance, value):
value = super(ShapeParam, self).coerce(instance, value)
for i, v in enumerate(value):
if not is_integer(v):
raise ValidationError("Element %d must be an int (got type %r)"
% (i, type(v).__name__),
attr=self.name, obj=instance)
if self.low is not None and v < self.low:
raise ValidationError(
"Element %d must be >= %d (got %d)" % (i, self.low, v),
attr=self.name, obj=instance)
def __pow__(self, other):
if not is_integer(other):
return NotImplemented
n, d = self.tf
if other > 0:
return LinearSystem(normalize(n**other, d**other), self.analog)
elif other < 0:
return LinearSystem(normalize(d**-other, n**-other), self.analog)
else:
assert other == 0
return LinearSystem(1., self.analog)
def BoxFilter(width, normalized=True):
"""A discrete box-filter with a given ``width``, and optionally unit area.
This filter is also known as a "box blur", and has the effect of
smoothing out the input signal by taking its rolling mean over a finite
number of time-steps. Its properties are qualitatively similar to the
continuous-time :func:`.Lowpass`.
Parameters
----------
width : ``integer``
Width of the box-filter (in time-steps).
normalized : ``boolean``, optional
If ``True``, then the height of the box-filter is ``1/width``,
otherwise ``1``. Defaults to ``True``.
Returns
-------
sys : :class:`.LinearSystem`
Digital system implementing the box-filter.
See Also
--------
:attr:`.z`
:func:`.Lowpass`
Examples
--------
Simulate a Nengo network using a box filter of 10 ms for a synapse:
>>> from nengolib.synapses import BoxFilter
>>> import nengo
>>> with nengo.Network() as model:
>>> stim = nengo.Node(output=lambda _: np.random.randn(1))
>>> p_stim = nengo.Probe(stim)
>>> p_box = nengo.Probe(stim, synapse=BoxFilter(10))
>>> with nengo.Simulator(model) as sim:
>>> sim.run(.1)
>>> import matplotlib.pyplot as plt
>>> plt.step(sim.trange(), sim.data[p_stim], label="Noisy Input", alpha=.5)
>>> plt.step(sim.trange(), sim.data[p_box], label="Box-Filtered")
>>> plt.xlabel("Time (s)")
>>> plt.legend()
>>> plt.show()
"""
if not is_integer(width) or width <= 0:
raise ValueError("width (%s) must be positive integer" % (width, ))
den = DiscreteDelay(width - 1)
amplitude = 1. / width if normalized else 1.
# 1 + 1/z + ... + 1/z^(steps) = (z^steps + z^(steps-1) + ... + 1)/z^steps
return amplitude * sum(z**k for k in range(width)) * den
def sample(self, num, d=None, rng=np.random):
num, d = self._sample_shape(num, d)
if d == 1:
# Tile the points optimally. TODO: refactor
return np.linspace(1./num, 1, num)[:, None]
if d is None or not is_integer(d) or d < 1:
# TODO: this should be raised when the ensemble is created
raise ValueError("d (%d) must be positive integer" % d)
if d > 40:
warnings.warn("i4_sobol_generate does not support d > 40; "
"falling back to monte-carlo method", UserWarning)
return np.random.uniform(size=(num, d))
return i4_sobol_generate(d, num, skip=0)
def DiscreteDelay(steps):
"""A discrete (pure) time-delay: ``z**-steps``.
Also equivalent to ``(~z)**steps`` or ``1/z**steps``.
Parameters
----------
steps : ``integer``
Number of time-steps to delay the input signal.
Returns
-------
sys : :class:`.LinearSystem`
Digital filter implementing the pure delay exactly.
See Also
--------
:attr:`.z`
:func:`.PadeDelay`
Notes
-----
A single step of the delay will be removed if using the ``filt`` method.
This is done for subtle reasons of consistency with Nengo.
The correct delay will appear when passed to :class:`nengo.Connection`.
Examples
--------
Simulate a Nengo network using a discrete delay of half a second for a
synapse:
>>> from nengolib.synapses import DiscreteDelay
>>> import nengo
>>> with nengo.Network() as model:
>>> stim = nengo.Node(output=lambda t: np.sin(2*np.pi*t))
>>> p_stim = nengo.Probe(stim)
>>> p_delay = nengo.Probe(stim, synapse=DiscreteDelay(500))
>>> with nengo.Simulator(model) as sim:
>>> sim.run(1.)
>>> import matplotlib.pyplot as plt
>>> plt.plot(sim.trange(), sim.data[p_stim], label="Stimulus")
>>> plt.plot(sim.trange(), sim.data[p_delay], label="Delayed")
>>> plt.xlabel("Time (s)")
>>> plt.legend()
>>> plt.show()
"""
if not is_integer(steps) or steps < 0:
raise ValueError("steps (%s) must be non-negative integer" % (steps, ))
return z**-steps
def __init__(self, data, rng=None):
if is_integer(data):
if data < 1:
raise Exception("number of dimensions must be a positive int")
self.randomize(data, rng=rng)
else:
try:
len(data)
except:
raise Exception("Must specify either the data or the length "
"for a SemanticPointer.")
self.v = np.array(data, dtype=float)
if len(self.v.shape) != 1:
raise Exception("data must be a vector")
def sample(self, n, d=1, rng=np.random):
"""Samples ``n`` points in ``d`` dimensions."""
if d == 1:
# Tile the points optimally. TODO: refactor
return np.linspace(1. / n, 1, n)[:, None]
if d is None or not is_integer(d) or d < 1:
# TODO: this should be raised when the ensemble is created
raise ValueError("d (%d) must be positive integer" % d)
if d > 40:
warnings.warn(
"i4_sobol_generate does not support d > 40; "
"falling back to Monte Carlo method", UserWarning)
return rng.uniform(size=(n, d))
return i4_sobol_generate(d, n, skip=0)
def Highpass(tau, order=1):
"""A differentiated lowpass of given order: ``(tau*s/(tau*s + 1))**order``.
Equivalent to differentiating the input, scaling by ``tau``,
lowpass filtering with time-constant ``tau``, and finally repeating
this ``order`` times. The lowpass filter is required to make this causal.
Parameters
----------
tau : ``float``
Time-constant of the lowpass filter, and highpass gain.
order : ``integer``, optional
Dimension of the resulting linear system. Defaults to ``1``.
Returns
-------
sys : :class:`.LinearSystem`
Highpass filter with time-constant ``tau`` and dimension ``order``.
See Also
--------
:func:`.Lowpass`
:attr:`.s`
Examples
--------
>>> from nengolib.synapses import Highpass
Evaluate the highpass in the frequency domain with a time-constant of 10 ms
and with a variety of orders:
>>> tau = 1e-2
>>> orders = list(range(1, 9))
>>> freqs = np.linspace(0, 50, 100) # to evaluate
>>> import matplotlib.pyplot as plt
>>> plt.title(r"$\\tau=%s$" % tau)
>>> for order in orders:
>>> sys = Highpass(tau, order)
>>> assert len(sys) == order
>>> plt.plot(freqs, np.abs(sys.evaluate(freqs)),
>>> label=r"order=%s" % order)
>>> plt.xlabel("Frequency (Hz)")
>>> plt.legend()
>>> plt.show()
"""
if order < 1 or not is_integer(order):
raise ValueError("order (%s) must be integer >= 1" % order)
return (tau * s * Lowpass(tau))**order
def __init__(self, data, rng=None):
if is_integer(data):
if data < 1:
raise Exception("number of dimensions must be a positive int")
self.randomize(data, rng=rng)
else:
try:
len(data)
except:
raise Exception("Must specify either the data or the length "
"for a SemanticPointer.")
self.v = np.array(data, dtype=float)
if len(self.v.shape) != 1:
raise Exception("data must be a vector")
def coerce(self, instance, value):
value = super(VocabularyOrDimParam, self).coerce(instance, value)
if value is not None:
if is_integer(value):
if value < 1:
raise ValidationError(
"Vocabulary dimensionality must be at least 1.",
attr=self.name, obj=instance)
value = instance.vocabs.get_or_create(value)
elif not isinstance(value, Vocabulary):
raise ValidationError(
"Must be of type 'Vocabulary' or an integer (got type %r)."
% type(value).__name__, attr=self.name, obj=instance)
return value
def __getitem__(self, item):
"""Index or slice into array"""
if not isinstance(item, tuple):
item = (item, )
if not all(is_integer(i) or isinstance(i, slice) for i in item):
raise SignalError("Can only index or slice into signals")
if all(map(is_integer, item)):
# turn one index into slice to get a view from numpy
item = item[:-1] + (slice(item[-1], item[-1] + 1), )
return Signal(self._initial_value[item],
name="%s[%s]" % (self.name, item),
base=self.base)
def __getitem__(self, item):
"""Index or slice into array"""
if not isinstance(item, tuple):
item = (item,)
if not all(is_integer(i) or isinstance(i, slice) for i in item):
raise SignalError("Can only index or slice into signals")
if all(map(is_integer, item)):
# turn one index into slice to get a view from numpy
item = item[:-1] + (slice(item[-1], item[-1]+1),)
return Signal(self._initial_value[item],
name="%s[%s]" % (self.name, item),
base=self.base)
def __init__(self, data, rng=None):
if is_integer(data):
if data < 1:
raise ValidationError("Number of dimensions must be a "
"positive int", attr='data', obj=self)
self.randomize(data, rng=rng)
else:
try:
len(data)
except:
raise ValidationError(
"Must specify either the data or the length for a "
"SemanticPointer.", attr='data', obj=self)
self.v = np.array(data, dtype=float)
if len(self.v.shape) != 1:
raise ValidationError("'data' must be a vector", 'data', self)
def __init__(self, dimensions, randomize=True, unitary=False, max_similarity=0.1, include_pairs=False, rng=None):
if not is_integer(dimensions):
raise TypeError("dimensions must be an integer")
if dimensions < 1:
raise ValueError("dimensions must be positive")
self.dimensions = dimensions
self.randomize = randomize
self.unitary = unitary
self.max_similarity = max_similarity
self.pointers = {}
self.keys = []
self.key_pairs = None
self.vectors = np.zeros((0, dimensions), dtype=float)
self.vector_pairs = None
self._include_pairs = None
self.include_pairs = include_pairs
self._identity = None
self.rng = rng
def __getitem__(self, item):
"""Index or slice into array"""
if item is Ellipsis or (
isinstance(item, slice) and item == slice(None)):
return self
if not isinstance(item, tuple):
item = (item,)
if not all(is_integer(i) or isinstance(i, slice) for i in item):
raise SignalError("Can only index or slice into signals")
if all(map(is_integer, item)):
# turn one index into slice to get a view from numpy
item = item[:-1] + (slice(item[-1], item[-1]+1),)
view = self._initial_value[item]
offset = (npext.array_offset(view)
- npext.array_offset(self._initial_value))
return Signal(view, name="%s[%s]" % (self.name, item),
base=self.base, offset=offset)
def __init__(self, dimensions, randomize=True, unitary=False,
max_similarity=0.1, include_pairs=False, rng=None):
if not is_integer(dimensions) or dimensions < 1:
raise ValidationError("dimensions must be a positive integer",
attr='dimensions', obj=self)
self.dimensions = dimensions
self.randomize = randomize
self.unitary = unitary
self.max_similarity = max_similarity
self.pointers = {}
self.keys = []
self.key_pairs = None
self.vectors = np.zeros((0, dimensions), dtype=float)
self.vector_pairs = None
self._include_pairs = None
self.include_pairs = include_pairs
self._identity = None
self.rng = rng
self.readonly = False
self.parent = None
def one_hot_from_labels(labels, classes=None, dtype=float):
"""Turn integer labels into a one-hot encoding.
Parameters
==========
labels : (n,) array
Labels to turn into one-hot encoding.
classes : int or (n_classes,) array (optional)
Classes for encoding. If integer and ``labels.dtype`` is integer, this
is the number of classes in the encoding. If iterable, this is the
list of classes to place in the one-hot (must be a superset of the
unique elements in ``labels``).
dtype : dtype (optional)
Data type of returned one-hot encoding (defaults to ``float``).
"""
assert labels.ndim == 1
n = labels.shape[0]
if np.issubdtype(labels.dtype, np.integer) and (classes is None
or is_integer(classes)):
index = labels
index_min, index_max = index.min(), index.max()
n_classes = (index_max + 1) if classes is None else classes
assert index_min >= 0
assert index_max < n_classes
else:
if classes is not None:
assert is_iterable(classes)
assert set(np.unique(labels)).issubset(classes)
classes = np.unique(labels) if classes is None else classes
n_classes = len(classes)
c_index = np.argsort(classes)
c_sorted = classes[c_index]
index = c_index[np.searchsorted(c_sorted, labels)]
y = np.zeros((n, n_classes), dtype=dtype)
y[np.arange(n), index] = 1
return y
def __init__(self, obj, key=slice(None)):
self.obj = obj
if is_integer(key):
# single slices of the form [i] should be cast into
# slice objects for convenience
if key == -1:
# special case because slice(-1, 0) gives the empty list
key = slice(key, None)
else:
key = slice(key, key+1)
self.slice = key
# Node.size_in != size_out, so one of these can be invalid
try:
self.size_in = np.arange(self.obj.size_in)[self.slice].size
except IndexError:
self.size_in = None
try:
self.size_out = np.arange(self.obj.size_out)[self.slice].size
except IndexError:
self.size_out = None
if self.size_in is None and self.size_out is None:
raise ValidationError("Invalid slice '%s' of %s"
% (self.slice, self.obj), attr='key')
def build_connection(conn, model): # noqa: C901
rng = np.random.RandomState(model.next_seed())
model.sig_in[conn] = model.sig_out[conn.pre]
model.sig_out[conn] = model.sig_in[conn.post]
decoders = None
eval_points = None
solver_info = None
transform = np.array(conn.transform_full, dtype=np.float64)
# Figure out the signal going across this connection
if (isinstance(conn.pre, nengo.Ensemble)
and isinstance(conn.pre.neurons, nengo.Direct)):
# Decoded connection in directmode
if conn.function is None:
signal = model.sig_in[conn]
else:
sig_in, signal = build_pyfunc(fn=conn.function,
t_in=False,
n_in=model.sig_in[conn].size,
n_out=conn.dimensions,
label=conn.label,
model=model)
model.operators.append(
DotInc(model.sig_in[conn],
Signal(1.0, name="1"),
sig_in,
tag="%s input" % conn.label))
elif isinstance(conn.pre, nengo.Ensemble):
# Normal decoded connection
encoders = model.params[conn.pre].encoders
gain = model.params[conn.pre.neurons].gain
bias = model.params[conn.pre.neurons].bias
eval_points = conn.eval_points
if eval_points is None:
eval_points = npext.array(model.params[conn.pre].eval_points,
min_dims=2)
elif is_integer(eval_points):
eval_points = pick_eval_points(ens=conn.pre,
n_points=eval_points,
rng=rng)
else:
eval_points = npext.array(eval_points, min_dims=2)
x = np.dot(eval_points, encoders.T / conn.pre.radius)
activities = model.dt * conn.pre.neurons.rates(x, gain, bias)
if np.count_nonzero(activities) == 0:
raise RuntimeError(
"In '%s', for '%s', 'activites' matrix is all zero. "
"This is because no evaluation points fall in the firing "
"ranges of any neurons." % (str(conn), str(conn.pre)))
if conn.function is None:
targets = eval_points
else:
targets = np.zeros((len(eval_points), conn.function_size))
for i, ep in enumerate(eval_points):
targets[i] = conn.function(ep)
if conn.weight_solver is not None:
if conn.decoder_solver is not None:
raise ValueError("Cannot specify both 'weight_solver' "
"and 'decoder_solver'.")
# account for transform
targets = np.dot(targets, transform.T)
transform = np.array(1., dtype=np.float64)
decoders, solver_info = conn.weight_solver(
activities,
targets,
rng=rng,
E=model.params[conn.post].scaled_encoders.T)
model.sig_out[conn] = model.sig_in[conn.post.neurons]
signal_size = model.sig_out[conn].size
else:
solver = (conn.decoder_solver if conn.decoder_solver is not None
else nengo.decoders.lstsq_L2nz)
decoders, solver_info = solver(activities, targets, rng=rng)
signal_size = conn.dimensions
# Add operator for decoders and filtering
decoders = decoders.T
if conn.synapse is not None and conn.synapse > model.dt:
decay = decay_coef(pstc=conn.synapse, dt=model.dt)
decoder_signal = Signal(decoders * (1.0 - decay),
name="%s.decoders * (1 - decay)" %
conn.label)
else:
decoder_signal = Signal(decoders, name="%s.decoders" % conn.label)
decay = 0
signal = Signal(np.zeros(signal_size), name=conn.label)
model.operators.append(
ProdUpdate(decoder_signal,
model.sig_in[conn],
Signal(decay, name="decay"),
signal,
tag="%s decoding" % conn.label))
else:
# Direct connection
signal = model.sig_in[conn]
# Add operator for filtering (in the case filter wasn't already
# added, when pre.neurons is a non-direct Ensemble)
if decoders is None and conn.synapse is not None:
# Note: we add a filter here even if synapse < dt,
# in order to avoid cycles in the op graph. If the filter
# is explicitly set to None (e.g. for a passthrough node)
# then cycles can still occur.
signal = filtered_signal(signal, conn.synapse, model=model)
if conn.modulatory:
# Make a new signal, effectively detaching from post
model.sig_out[conn] = Signal(np.zeros(model.sig_out[conn].size),
name="%s.mod_output" % conn.label)
# Add reset operator?
# TODO: add unit test
# Add operator for transform
if isinstance(conn.post, nengo.objects.Neurons):
if not model.has_built(conn.post):
# Since it hasn't been built, it wasn't added to the Network,
# which is most likely because the Neurons weren't associated
# with an Ensemble.
raise RuntimeError("Connection '%s' refers to Neurons '%s' "
"that are not a part of any Ensemble." %
(conn, conn.post))
transform *= model.params[conn.post].gain[:, np.newaxis]
model.operators.append(
DotInc(Signal(transform, name="%s.transform" % conn.label),
signal,
model.sig_out[conn],
tag=conn.label))
# Set up probes
for probe in conn.probes["signal"]:
Builder.build(probe, dimensions=model.sig_out[conn].size, model=model)
model.params[conn] = BuiltConnection(decoders=decoders,
eval_points=eval_points,
transform=transform,
solver_info=solver_info)
def build_connection(self, conn):
dt = self.model.dt
rng = np.random.RandomState(self.next_seed())
self.model.sig_in[conn] = self.model.sig_out[conn.pre]
self.model.sig_out[conn] = self.model.sig_in[conn.post]
decoders = None
eval_points = None
transform = np.array(conn.transform_full, dtype=np.float64)
# Figure out the signal going across this connection
if (isinstance(conn.pre, nengo.Ensemble)
and isinstance(conn.pre.neurons, nengo.Direct)):
# Decoded connection in directmode
if conn.function is None:
signal = self.model.sig_in[conn]
else:
sig_in, signal = self.build_pyfunc(
fn=conn.function,
t_in=False,
n_in=self.model.sig_in[conn].size,
n_out=conn.dimensions,
label=conn.label)
self.model.operators.append(DotInc(
self.model.sig_in[conn],
Signal(1.0, name="1"),
sig_in,
tag="%s input" % conn.label))
elif isinstance(conn.pre, nengo.Ensemble):
# Normal decoded connection
encoders = self.built[conn.pre].encoders
gain = self.built[conn.pre.neurons].gain
bias = self.built[conn.pre.neurons].bias
eval_points = conn.eval_points
if eval_points is None:
eval_points = npext.array(
self.built[conn.pre].eval_points, min_dims=2)
elif is_integer(eval_points):
eval_points = self.generate_eval_points(
ens=conn.pre, n_points=eval_points, rng=rng)
else:
eval_points = npext.array(eval_points, min_dims=2)
x = np.dot(eval_points, encoders.T / conn.pre.radius)
activities = dt * conn.pre.neurons.rates(x, gain, bias)
if np.count_nonzero(activities) == 0:
raise RuntimeError(
"In '%s', for '%s', 'activities' matrix is all zero. "
"This is because no evaluation points fall in the firing "
"ranges of any neurons." % (str(conn), str(conn.pre)))
if conn.function is None:
targets = eval_points
else:
targets = npext.array(
[conn.function(ep) for ep in eval_points], min_dims=2)
if conn.weight_solver is not None:
if conn.decoder_solver is not None:
raise ValueError("Cannot specify both 'weight_solver' "
"and 'decoder_solver'.")
# account for transform
targets = np.dot(targets, transform.T)
transform = np.array(1., dtype=np.float64)
decoders = conn.weight_solver(
activities, targets, rng=rng,
E=self.built[conn.post].scaled_encoders.T)
self.model.sig_out[conn] = self.model.sig_in[
conn.post.neurons]
signal_size = self.model.sig_out[conn].size
else:
solver = (conn.decoder_solver if conn.decoder_solver is
not None else nengo.decoders.lstsq_L2nz)
decoders = solver(activities, targets, rng=rng)
signal_size = conn.dimensions
# Add operator for decoders and filtering
decoders = decoders.T
if conn.filter is not None and conn.filter > dt:
o_coef, n_coef = self.filter_coefs(pstc=conn.filter, dt=dt)
decoder_signal = Signal(
decoders * n_coef,
name="%s.decoders * n_coef" % conn.label)
else:
decoder_signal = Signal(decoders,
name="%s.decoders" % conn.label)
o_coef = 0
signal = Signal(np.zeros(signal_size), name=conn.label)
self.model.operators.append(ProdUpdate(
decoder_signal,
self.model.sig_in[conn],
Signal(o_coef, name="o_coef"),
signal,
tag="%s decoding" % conn.label))
else:
# Direct connection
signal = self.model.sig_in[conn]
# Add operator for filtering (in the case filter wasn't already
# added, when pre.neurons is a non-direct Ensemble)
if decoders is None and conn.filter is not None:
# Note: we add a filter here even if filter < dt,
# in order to avoid cycles in the op graph. If the filter
# is explicitly set to None (e.g. for a passthrough node)
# then cycles can still occur.
signal = self.filtered_signal(signal, conn.filter)
if conn.modulatory:
# Make a new signal, effectively detaching from post
self.model.sig_out[conn] = Signal(
np.zeros(self.model.sig_out[conn].size),
name="%s.mod_output" % conn.label)
# Add reset operator?
# TODO: add unit test
# Add operator for transform
if isinstance(conn.post, nengo.objects.Neurons):
if not self.has_built(conn.post):
# Since it hasn't been built, it wasn't added to the Network,
# which is most likely because the Neurons weren't associated
# with an Ensemble.
raise RuntimeError("Connection '%s' refers to Neurons '%s' "
"that are not a part of any Ensemble." % (
conn, conn.post))
transform *= self.built[conn.post].gain[:, np.newaxis]
self.model.operators.append(
DotInc(Signal(transform, name="%s.transform" % conn.label),
signal,
self.model.sig_out[conn],
tag=conn.label))
# Set up probes
for probe in conn.probes["signal"]:
self.build(probe, dimensions=self.model.sig_out[conn].size)
return BuiltConnection(decoders=decoders,
eval_points=eval_points,
transform=transform)
def build_ensemble(self, ens):
# Create random number generator
seed = self.next_seed() if ens.seed is None else ens.seed
rng = np.random.RandomState(seed)
# Generate eval points
if ens.eval_points is None or is_integer(ens.eval_points):
eval_points = self.generate_eval_points(
ens=ens, n_points=ens.eval_points, rng=rng)
else:
eval_points = npext.array(
ens.eval_points, dtype=np.float64, min_dims=2)
# Set up signal
self.model.sig_in[ens] = Signal(np.zeros(ens.dimensions),
name="%s.signal" % ens.label)
self.model.operators.append(Reset(self.model.sig_in[ens]))
# Set up encoders
if ens.encoders is None:
if isinstance(ens.neurons, nengo.Direct):
encoders = np.identity(ens.dimensions)
else:
sphere = dists.UniformHypersphere(ens.dimensions, surface=True)
encoders = sphere.sample(ens.neurons.n_neurons, rng=rng)
else:
encoders = np.array(ens.encoders, dtype=np.float64)
enc_shape = (ens.neurons.n_neurons, ens.dimensions)
if encoders.shape != enc_shape:
raise ShapeMismatch(
"Encoder shape is %s. Should be (n_neurons, dimensions); "
"in this case %s." % (encoders.shape, enc_shape))
encoders /= npext.norm(encoders, axis=1, keepdims=True)
# Determine max_rates and intercepts
if isinstance(ens.max_rates, dists.Distribution):
max_rates = ens.max_rates.sample(
ens.neurons.n_neurons, rng=rng)
else:
max_rates = np.array(ens.max_rates)
if isinstance(ens.intercepts, dists.Distribution):
intercepts = ens.intercepts.sample(
ens.neurons.n_neurons, rng=rng)
else:
intercepts = np.array(ens.intercepts)
# Build the neurons
if isinstance(ens.neurons, nengo.Direct):
bn = self.build(ens.neurons, ens.dimensions)
else:
bn = self.build(ens.neurons, max_rates, intercepts)
# Scale the encoders
if isinstance(ens.neurons, nengo.Direct):
scaled_encoders = encoders
else:
scaled_encoders = encoders * (bn.gain / ens.radius)[:, np.newaxis]
# Create output signal, using built Neurons
self.model.operators.append(DotInc(
Signal(scaled_encoders, name="%s.scaled_encoders" % ens.label),
self.model.sig_in[ens],
self.model.sig_in[ens.neurons],
tag="%s encoding" % ens.label))
# Output is neural output
self.model.sig_out[ens] = self.model.sig_out[ens.neurons]
for probe in ens.probes["decoded_output"]:
self.build(probe, dimensions=ens.dimensions)
for probe in ens.probes["spikes"] + ens.probes["voltages"]:
self.build(probe, dimensions=ens.neurons.n_neurons)
return BuiltEnsemble(eval_points=eval_points,
encoders=encoders,
intercepts=intercepts,
max_rates=max_rates,
scaled_encoders=scaled_encoders)
def DiscreteDelay(steps):
"""Delays its input signal by a fixed number of timesteps."""
if not is_integer(steps) or steps < 0:
raise ValueError("steps (%s) must be non-negative integer" % (steps,))
return z**(-steps)
def validate(self, instance, num):
if num is not None and not is_integer(num):
raise ValidationError("Must be an integer; got '%s'" % num,
attr=self.name,
obj=instance)
super(IntParam, self).validate(instance, num)
def Highpass(tau, order=1):
"""Differentiated lowpass, raised to a given power."""
if order < 1 or not is_integer(order):
raise ValueError("order (%s) must be integer >= 1" % order)
num, den = map(np.poly1d, ([tau, 0], [tau, 1]))
return LinearFilter(num**order, den**order)
def add_spikes(self, ti, spike_idxs):
assert is_integer(ti)
ti = int(ti)
assert ti > 0, "Spike times must be >= 1 (got %d)" % ti
assert ti not in self.spikes
self.spikes[ti] = spike_idxs
def validate(self, instance, num):
if num is not None and not is_integer(num):
raise ValueError("Must be an integer; got '%s'" % num)
super(IntParam, self).validate(instance, num)
def coerce_defaults(self):
if self.shape is None:
return True
return all(is_integer(dim) or dim in ('...', '*')
for dim in self.shape)
def coerce_defaults(self):
return all(
is_integer(dim) or dim in ('...', '*') for dim in self.shape)
def build_ensemble(ens, model): # noqa: C901
# Create random number generator
seed = model.next_seed() if ens.seed is None else ens.seed
rng = np.random.RandomState(seed)
# Generate eval points
if ens.eval_points is None or is_integer(ens.eval_points):
eval_points = pick_eval_points(ens=ens,
n_points=ens.eval_points,
rng=rng)
else:
eval_points = npext.array(ens.eval_points,
dtype=np.float64,
min_dims=2)
# Set up signal
model.sig_in[ens] = Signal(np.zeros(ens.dimensions),
name="%s.signal" % ens.label)
model.operators.append(Reset(model.sig_in[ens]))
# Set up encoders
if ens.encoders is None:
if isinstance(ens.neurons, nengo.Direct):
encoders = np.identity(ens.dimensions)
else:
sphere = dists.UniformHypersphere(ens.dimensions, surface=True)
encoders = sphere.sample(ens.neurons.n_neurons, rng=rng)
else:
encoders = np.array(ens.encoders, dtype=np.float64)
enc_shape = (ens.neurons.n_neurons, ens.dimensions)
if encoders.shape != enc_shape:
raise ShapeMismatch(
"Encoder shape is %s. Should be (n_neurons, dimensions); "
"in this case %s." % (encoders.shape, enc_shape))
encoders /= npext.norm(encoders, axis=1, keepdims=True)
# Determine max_rates and intercepts
if isinstance(ens.max_rates, dists.Distribution):
max_rates = ens.max_rates.sample(ens.neurons.n_neurons, rng=rng)
else:
max_rates = np.array(ens.max_rates)
if isinstance(ens.intercepts, dists.Distribution):
intercepts = ens.intercepts.sample(ens.neurons.n_neurons, rng=rng)
else:
intercepts = np.array(ens.intercepts)
# Build the neurons
if isinstance(ens.neurons, nengo.Direct):
Builder.build(ens.neurons, ens.dimensions, model=model)
else:
Builder.build(ens.neurons, max_rates, intercepts, model=model)
bn = model.params[ens.neurons]
# Scale the encoders
if isinstance(ens.neurons, nengo.Direct):
scaled_encoders = encoders
else:
scaled_encoders = encoders * (bn.gain / ens.radius)[:, np.newaxis]
# Create output signal, using built Neurons
model.operators.append(
DotInc(Signal(scaled_encoders, name="%s.scaled_encoders" % ens.label),
model.sig_in[ens],
model.sig_in[ens.neurons],
tag="%s encoding" % ens.label))
# Output is neural output
model.sig_out[ens] = model.sig_out[ens.neurons]
for probe in ens.probes["decoded_output"]:
Builder.build(probe, dimensions=ens.dimensions, model=model)
for probe in ens.probes["spikes"] + ens.probes["voltages"]:
Builder.build(probe, dimensions=ens.neurons.n_neurons, model=model)
model.params[ens] = BuiltEnsemble(eval_points=eval_points,
encoders=encoders,
intercepts=intercepts,
max_rates=max_rates,
scaled_encoders=scaled_encoders)
def validate(self, instance, num):
if num is not None and not is_integer(num):
raise ValueError("Must be an integer; got '%s'" % num)
super(IntParam, self).validate(instance, num)
def validate(self, instance, num):
if num is not None and not is_integer(num):
raise ValidationError("Must be an integer; got '%s'" % num,
attr=self.name, obj=instance)
super(IntParam, self).validate(instance, num)
