def __init__(
self, X, prior, alpha, K, assignments="rand",
covariance_type="full"
):
self.alpha = alpha
N, D = X.shape
# Initial component assignments
if assignments == "rand":
assignments = np.random.randint(0, K, N)
# Make sure we have consequetive values
for k in xrange(assignments.max()):
while len(np.nonzero(assignments == k)[0]) == 0:
assignments[np.where(assignments > k)] -= 1
if assignments.max() == k:
break
elif assignments == "each-in-own":
assignments = np.arange(N)
else:
# assignments is a vector
pass
if covariance_type == "full":
self.components = GaussianComponents(X, prior, assignments, K_max=K)
elif covariance_type == "diag":
self.components = GaussianComponentsDiag(X, prior, assignments, K_max=K)
elif covariance_type == "fixed":
self.components = GaussianComponentsFixedVar(X, prior, assignments, K_max=K)
else:
assert False, "Invalid covariance type."
def setup_components(self, K, assignments="rand", X=None):
"""
Setup the `components` attribute.
See parameters of `FBGMM` for parameters not described below. This
function is also useful for resetting the `components`, e.g. if you
want to change the maximum number of possible components.
Parameters
----------
X : NxD matrix or None
The data matrix. If None, then it is assumed that the `components`
attribute has already been initialized and that this function is
called to reset the `components`; in this case the data is taken
from the previous initialization.
"""
if X is None:
assert hasattr(self, "components")
X = self.components.X
N, D = X.shape
# Initial component assignments
if isinstance(assignments, basestring) and assignments == "rand":
assignments = np.random.randint(0, K, N)
elif isinstance(assignments,
basestring) and assignments == "each-in-own":
assignments = np.arange(N)
else:
# `assignments` is a vector
pass
# Make sure we have consequetive values
for k in xrange(assignments.max()):
while len(np.nonzero(assignments == k)[0]) == 0:
assignments[np.where(assignments > k)] -= 1
if assignments.max() == k:
break
if self.covariance_type == "full":
self.components = GaussianComponents(X,
self.prior,
assignments,
K_max=K)
elif self.covariance_type == "diag":
self.components = GaussianComponentsDiag(X,
self.prior,
assignments,
K_max=K)
elif self.covariance_type == "fixed":
self.components = GaussianComponentsFixedVar(X,
self.prior,
assignments,
K_max=K)
else:
assert False, "Invalid covariance type."