def mode(keys,
axis=semantics.axis_default,
weights=None,
return_indices=False):
"""compute the mode, or most frequent occuring key in a set
Parameters
----------
keys : ndarray, [n_keys, ...]
input array. elements of 'keys' can have arbitrary shape or dtype
weights : ndarray, [n_keys], optional
if given, the contribution of each key to the mode is weighted by the given weights
return_indices : bool
if True, return all indices such that keys[indices]==mode holds
Returns
-------
mode : ndarray, [...]
the most frequently occuring key in the key sequence
indices : ndarray, [mode_multiplicity], int, optional
if return_indices is True, all indices such that points[indices]==mode holds
"""
index = as_index(keys, axis)
if weights is None:
unique, weights = count(index)
else:
unique, weights = group_by(index).sum(weights)
bin = np.argmax(weights)
_mode = unique[
bin] # FIXME: replace with index.take for lexindex compatibility?
if return_indices:
indices = index.sorter[index.start[bin]:index.stop[bin]]
return _mode, indices
else:
return _mode
def max(self, values, default=None):
if default is None:
try:
info = np.iinfo(values.dtype)
default = info.min
except:
default = -np.inf
table = self.allocate(values.dtype, default)
keys, values = group_by(self.keys).max(values)
table[self.get_inverses(keys)] = values
return tuple(self.uniques), table
def last(self, values):
table = self.allocate(np.float, np.nan)
keys, values = group_by(self.keys).last(values)
table[self.get_inverses(keys)] = values
return tuple(self.uniques), table
def sum(self, values):
table = self.allocate(values.dtype)
keys, values = group_by(self.keys).sum(values)
table[self.get_inverses(keys)] = values
return tuple(self.uniques), table
