def __getitem__(self, spec):
_get = super(Dimension, self).__getitem__
if spec is None:
return _get(slice(None))
try:
if iss.issequence(spec):
return tuple(map(_get, spec))
if not callable(spec):
return _get(spec)
except:
raise IndexError, 'invalid index for dimension "%s" (%r)' \
% (self.name, spec)
try:
return tuple(v for i, v in enumerate(self)
if spec(i, v))
except Exception, e:
raise type(e), 'predicate error for dimension "%s" (%s)' \
% (self.name, e)
def mu_sigma(hbrick, axes, newdim=(u'stat', (u'mean', u'stddev'))):
"""Compute mean and stddev over all the specified axes.
hbrick: an (n-dimensional) HyperBrick object;
axes: either a k-tuple of integers or strings, or a string
describing a space-separated list of k dimension names or
dimension indices (integers);
newdim: a pair whose first element should be a string and second
element a 2-tuple of strings; this pair serves as the
specification (name and levels) for the last dimension of
the returned HyperBrick;
default: (u'stat', (u'mean', u'stddev'))
returns: a HyperBrick object, whose _data attribute contains the
ndarray computed by _mu_sigma(hbrick._data, indices)
(where indices holds the integer equivalents of the axes
specified in the axes parameter); the first n-k
dimensions of the returned HyperBrick are the same as the
dimensions of hbrick that were not specified in the axes
parameter, and whose last dimension is a 2-level
dimension; the hyperslab corresponding to the first and
second levels of this last dimension are, respectively,
the computed means and stddevs; the ordering of the first
n-k (i.e. the kept) dimensions is the same as it was in
hbrick.
"""
# the next line allows us to pass several named dimensions as a
# single space-separated string.
if not iss.issequence(axes): axes = axes.split()
# we convert (as necessary) the dimensions specified in axes to
# numerical indices;
axes = tuple(map(hbrick._toaxis, axes))
data = _mu_sigma(hbrick._data, axes)
newdims = [hbrick._fromaxis(i)
for i in range(hbrick.ndim)
if i not in set(axes)] + [newdim]
return hb.HyperBrick(data, newdims)
