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import numpy as np
from Orange import data
def _get_variable(variable, dat, attr_name, expected_type=None, expected_name=""):
failed = False
if isinstance(variable, data.Variable):
datvar = getattr(dat, "variable", None)
if datvar is not None and datvar is not variable:
raise ValueError("variable does not match the variable in the data")
elif hasattr(dat, "domain"):
variable = dat.domain[variable]
elif hasattr(dat, attr_name):
variable = dat.variable
else:
failed = True
if failed or (expected_type is not None and not isinstance(variable, expected_type)):
if not expected_type or isinstance(variable, data.Variable):
raise ValueError("expected %s variable not %s" % (expected_name, variable))
else:
raise ValueError("expected %s, not '%s'" % (
expected_type.__name__, type(variable).__name__))
return variable
def _create_discrete(cls, *args):
return cls(*args)
class Discrete(np.ndarray):
def __new__(cls, dat, col_variable=None, row_variable=None,
row_unknowns=None, col_unknowns=None, unknowns=None):
if isinstance(dat, data.Storage):
if unknowns is not None or row_unknowns is not None or \
col_unknowns is not None:
raise TypeError(
"incompatible arguments (data storage and 'unknowns'")
return cls.from_data(dat, col_variable, row_variable)
if row_variable is not None:
row_variable = _get_variable(row_variable, dat, "row_variable")
if col_variable is not None:
col_variable = _get_variable(col_variable, dat, "col_variable")
self = super().__new__(cls, dat.shape)
self.row_variable = row_variable
self.col_variable = col_variable
self.col_unknowns = np.zeros(dat.shape[0]) \
if col_unknowns is None else col_unknowns
self.row_unknowns = np.zeros(dat.shape[1]) \
if col_unknowns is None else row_unknowns
self.unknowns = unknowns or 0
self[...] = dat
return self
@classmethod
def from_data(cls, data, col_variable, row_variable=None):
if row_variable is None:
row_variable = data.domain.class_var
if row_variable is None:
raise ValueError(
"row_variable needs to be specified (data has no class)")
row_variable = _get_variable(row_variable, data, "row_variable")
col_variable = _get_variable(col_variable, data, "col_variable")
try:
dist, col_unknowns, row_unknowns, unknowns = \
data._compute_contingency([col_variable], row_variable)[0]
self = super().__new__(cls, dist.shape)
self[...] = dist
self.col_unknowns = col_unknowns
self.row_unknowns = row_unknowns
self.unknowns = unknowns
except NotImplementedError:
shape = len(row_variable.values), len(col_variable.values)
self = super().__new__(cls, shape)
self[...] = np.zeros(shape)
self.col_unknowns = np.zeros(shape[0])
self.row_unknowns = np.zeros(shape[1])
self.unknowns = 0
rind = data.domain.index(row_variable)
cind = data.domain.index(col_variable)
for row in data:
rval, cval = row[rind], row[cind]
w = row.weight
if np.isnan(rval) and np.isnan(cval):
self.unknowns += w
elif np.isnan(rval):
self.row_unknowns[int(cval)] += w
elif np.isnan(cval):
self.col_unknowns[int(rval)] += w
else:
self[int(rval), int(cval)] += w
self.row_variable = row_variable
self.col_variable = col_variable
return self
@property
def array_with_unknowns(self):
"""
This property returns a contingency array with unknowns arrays added
as a column and row.
Returns
-------
np.array
Array with concatenated unknowns as a row and column
"""
return np.vstack(
(np.hstack((np.array(self), self.col_unknowns.reshape(-1, 1))),
np.append(self.row_unknowns, self.unknowns)))
def __eq__(self, other):
return (
np.array_equal(self, other) and
(not hasattr(other, "col_unknowns") or
np.array_equal(self.col_unknowns, other.col_unknowns)) and
(not hasattr(other, "row_unknowns") or
np.array_equal(self.row_unknowns, other.row_unknowns)) and
(not hasattr(other, "unknowns") or
self.unknowns == other.unknowns)
)
def __getitem__(self, index):
if isinstance(index, str):
if len(self.shape) == 2: # contingency
index = self.row_variable.to_val(index)
contingency_row = super().__getitem__(index)
contingency_row.col_variable = self.col_variable
return contingency_row
else: # Contingency row
column = self.strides == self.base.strides[:1]
if column:
index = self.row_variable.to_val(index)
else:
index = self.col_variable.to_val(index)
elif isinstance(index, tuple):
if isinstance(index[0], str):
index = (self.row_variable.to_val(index[0]), index[1])
if isinstance(index[1], str):
index = (index[0], self.col_variable.to_val(index[1]))
result = super().__getitem__(index)
if isinstance(result, Discrete):
if not isinstance(index, tuple):
result.col_unknowns = self.col_unknowns[index]
result.row_unknowns = self.row_unknowns
else:
result.col_unknowns = self.col_unknowns[index[0]]
result.row_unknowns = self.col_unknowns[index[1]]
result.unknowns = self.unknowns
if result.strides:
result.col_variable = self.col_variable
result.row_variable = self.row_variable
return result
def __setitem__(self, index, value):
if isinstance(index, str):
index = self.row_variable.to_val(index)
elif isinstance(index, tuple):
if isinstance(index[0], str):
index = (self.row_variable.to_val(index[0]), index[1])
if isinstance(index[1], str):
index = (index[0], self.col_variable.to_val(index[1]))
super().__setitem__(index, value)
def normalize(self, axis=None):
t = np.sum(self, axis=axis)
if t > 1e-6:
self[:] /= t
if axis is None or axis == 1:
self.unknowns /= t
def __reduce__(self):
return (
_create_discrete,
(Discrete, np.copy(self), self.col_variable, self.row_variable,
self.col_unknowns, self.row_unknowns, self.unknowns)
)
def __array_finalize__(self, obj):
# defined in __new__, pylint: disable=attribute-defined-outside-init
"""See http://docs.scipy.org/doc/numpy/user/basics.subclassing.html"""
if obj is None:
return
self.col_variable = getattr(obj, 'col_variable', None)
self.row_variable = getattr(obj, 'row_variable', None)
self.col_unknowns = getattr(obj, 'col_unknowns', None)
self.row_unknowns = getattr(obj, 'row_unknowns', None)
self.unknowns = getattr(obj, 'unknowns', None)
class Continuous:
def __init__(self, dat, col_variable=None, row_variable=None,
col_unknowns=None, row_unknowns=None, unknowns=None):
if isinstance(dat, data.Storage):
if unknowns is not None or row_unknowns is not None or \
col_unknowns is not None:
raise TypeError(
"incompatible arguments (data storage and 'unknowns'")
self.from_data(dat, col_variable, row_variable)
return
if row_variable is not None:
row_variable = _get_variable(row_variable, dat, "row_variable")
if col_variable is not None:
col_variable = _get_variable(col_variable, dat, "col_variable")
self.values, self.counts = dat
self.row_variable = row_variable
self.col_variable = col_variable
self.col_unknowns = np.zeros(self.counts.shape[1]) \
if col_unknowns is None else col_unknowns
self.row_unknowns = np.zeros(self.counts.shape[0]) \
if row_unknowns is None else row_unknowns
self.unknowns = unknowns or 0
def from_data(self, data, col_variable, row_variable=None):
if row_variable is None:
row_variable = data.domain.class_var
if row_variable is None:
raise ValueError("row_variable needs to be specified (data has no class)")
self.row_variable = _get_variable(row_variable, data, "row_variable")
self.col_variable = _get_variable(col_variable, data, "col_variable")
try:
conts = data._compute_contingency([col_variable], row_variable)
(self.values, self.counts), self.col_unknowns, self.row_unknowns, \
self.unknowns = conts[0]
except NotImplementedError:
raise NotImplementedError(
"Fallback method for computation of contingencies is not implemented yet"
)
@property
def array_with_unknowns(self):
"""
This function returns the list of all items returned by __getitem__
with adding a row of row_unknowns together with values.
"""
# pylint: disable=unnecessary-comprehension
other_rows = [x for x in self]
ind = self.row_unknowns > 0
unknown_rows = np.vstack((self.values[ind], self.row_unknowns[ind]))
return other_rows + [unknown_rows]
def __eq__(self, other):
return (
np.array_equal(self.values, other.values) and
np.array_equal(self.counts, other.counts) and
(not hasattr(other, "col_unknowns") or
np.array_equal(self.col_unknowns, other.col_unknowns)) and
(not hasattr(other, "row_unknowns") or
np.array_equal(self.row_unknowns, other.row_unknowns)) and
(not hasattr(other, "unknowns") or
self.unknowns == other.unknowns)
)
def __getitem__(self, index):
""" Return contingencies for a given class value. """
if isinstance(index, (str, float)):
index = self.row_variable.to_val(index)
C = self.counts[index]
ind = C > 0
return np.vstack((self.values[ind], C[ind]))
def __len__(self):
return self.counts.shape[0]
def __setitem__(self, index, value):
raise NotImplementedError(
"Setting individual class contingencies is not implemented yet. "
"Set .values and .counts."
)
def normalize(self, axis=None):
if axis is None:
t = sum(np.sum(x[:, 1]) for x in self)
if t > 1e-6:
for x in self:
x[:, 1] /= t
elif axis != 1:
raise ValueError(
"contingencies can be normalized only with axis=1 or without axis"
)
else:
for i, x in enumerate(self):
t = np.sum(x[:, 1])
if t > 1e-6:
x[:, 1] /= t
self.unknowns[i] /= t
else:
if self.unknowns[i] > 1e-6:
self.unknowns[i] = 1
def get_contingency(dat, col_variable, row_variable=None, col_unknowns=None,
row_unknowns=None, unks=None):
variable = _get_variable(col_variable, dat, "col_variable")
if variable.is_discrete:
return Discrete(
dat, col_variable, row_variable, col_unknowns, row_unknowns, unks)
elif variable.is_continuous:
return Continuous(
dat, col_variable, row_variable, col_unknowns, row_unknowns)
else:
raise TypeError(
"cannot compute distribution of '%s'" % type(variable).__name__)
def get_contingencies(dat, skip_discrete=False, skip_continuous=False):
vars = dat.domain.attributes
row_var = dat.domain.class_var
if row_var is None:
raise ValueError("data has no target variable")
if skip_discrete:
if skip_continuous:
return []
columns = [i for i, var in enumerate(vars) if var.is_continuous]
elif skip_continuous:
columns = [i for i, var in enumerate(vars) if var.is_discrete]
else:
columns = None
try:
dist_unks = dat._compute_contingency(columns)
if columns is None:
columns = np.arange(len(vars))
contigs = []
for col, (cont, col_unk, row_unk, unks) in zip(columns, dist_unks):
contigs.append(get_contingency(
cont, vars[col], row_var, col_unk, row_unk, unks))
except NotImplementedError:
if columns is None:
columns = range(len(vars))
contigs = [get_contingency(dat, i) for i in columns]
return contigs
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