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{{py:
implementation_specific_values = [
# Values are the following ones:
#
# name_suffix, INPUT_DTYPE_t, INPUT_DTYPE
#
# On the first hand, an empty string is used for `name_suffix`
# for the float64 case as to still be able to expose the original
# float64 implementation under the same API, namely `DistanceMetric`.
#
# On the other hand, '32' bit is used for `name_suffix` for the float32
# case to remove ambiguity and use `DistanceMetric32`, which is not
# publicly exposed.
#
# The metric mapping is adapted accordingly to route to the correct
# implementations.
#
# We also use 64bit types as defined in `sklearn.utils._typedefs`
# to maintain backward compatibility at the symbol level for extra
# safety.
#
('', 'DTYPE_t', 'DTYPE'),
('32', 'cnp.float32_t', 'np.float32')
]
}}
cimport numpy as cnp
from libc.math cimport sqrt, exp
from ..utils._typedefs cimport DTYPE_t, ITYPE_t, SPARSE_INDEX_TYPE_t
{{for name_suffix, INPUT_DTYPE_t, INPUT_DTYPE in implementation_specific_values}}
######################################################################
# Inline distance functions
#
# We use these for the default (euclidean) case so that they can be
# inlined. This leads to faster computation for the most common case
cdef inline DTYPE_t euclidean_dist{{name_suffix}}(
const {{INPUT_DTYPE_t}}* x1,
const {{INPUT_DTYPE_t}}* x2,
ITYPE_t size,
) nogil except -1:
cdef DTYPE_t tmp, d=0
cdef cnp.intp_t j
for j in range(size):
tmp = <DTYPE_t> (x1[j] - x2[j])
d += tmp * tmp
return sqrt(d)
cdef inline DTYPE_t euclidean_rdist{{name_suffix}}(
const {{INPUT_DTYPE_t}}* x1,
const {{INPUT_DTYPE_t}}* x2,
ITYPE_t size,
) nogil except -1:
cdef DTYPE_t tmp, d=0
cdef cnp.intp_t j
for j in range(size):
tmp = <DTYPE_t>(x1[j] - x2[j])
d += tmp * tmp
return d
cdef inline DTYPE_t euclidean_dist_to_rdist{{name_suffix}}(const {{INPUT_DTYPE_t}} dist) nogil except -1:
return dist * dist
cdef inline DTYPE_t euclidean_rdist_to_dist{{name_suffix}}(const {{INPUT_DTYPE_t}} dist) nogil except -1:
return sqrt(dist)
######################################################################
# DistanceMetric{{name_suffix}} base class
cdef class DistanceMetric{{name_suffix}}:
# The following attributes are required for a few of the subclasses.
# we must define them here so that cython's limited polymorphism will work.
# Because we don't expect to instantiate a lot of these objects, the
# extra memory overhead of this setup should not be an issue.
cdef DTYPE_t p
cdef DTYPE_t[::1] vec
cdef DTYPE_t[:, ::1] mat
cdef ITYPE_t size
cdef object func
cdef object kwargs
cdef DTYPE_t dist(
self,
const {{INPUT_DTYPE_t}}* x1,
const {{INPUT_DTYPE_t}}* x2,
ITYPE_t size,
) nogil except -1
cdef DTYPE_t rdist(
self,
const {{INPUT_DTYPE_t}}* x1,
const {{INPUT_DTYPE_t}}* x2,
ITYPE_t size,
) nogil except -1
cdef DTYPE_t dist_csr(
self,
const {{INPUT_DTYPE_t}}* x1_data,
const SPARSE_INDEX_TYPE_t[:] x1_indices,
const {{INPUT_DTYPE_t}}* x2_data,
const SPARSE_INDEX_TYPE_t[:] x2_indices,
const SPARSE_INDEX_TYPE_t x1_start,
const SPARSE_INDEX_TYPE_t x1_end,
const SPARSE_INDEX_TYPE_t x2_start,
const SPARSE_INDEX_TYPE_t x2_end,
const ITYPE_t size,
) nogil except -1
cdef DTYPE_t rdist_csr(
self,
const {{INPUT_DTYPE_t}}* x1_data,
const SPARSE_INDEX_TYPE_t[:] x1_indices,
const {{INPUT_DTYPE_t}}* x2_data,
const SPARSE_INDEX_TYPE_t[:] x2_indices,
const SPARSE_INDEX_TYPE_t x1_start,
const SPARSE_INDEX_TYPE_t x1_end,
const SPARSE_INDEX_TYPE_t x2_start,
const SPARSE_INDEX_TYPE_t x2_end,
const ITYPE_t size,
) nogil except -1
cdef int pdist(
self,
const {{INPUT_DTYPE_t}}[:, ::1] X,
DTYPE_t[:, ::1] D,
) except -1
cdef int cdist(
self,
const {{INPUT_DTYPE_t}}[:, ::1] X,
const {{INPUT_DTYPE_t}}[:, ::1] Y,
DTYPE_t[:, ::1] D,
) except -1
cdef int pdist_csr(
self,
const {{INPUT_DTYPE_t}}* x1_data,
const SPARSE_INDEX_TYPE_t[:] x1_indices,
const SPARSE_INDEX_TYPE_t[:] x1_indptr,
const ITYPE_t size,
DTYPE_t[:, ::1] D,
) nogil except -1
cdef int cdist_csr(
self,
const {{INPUT_DTYPE_t}}* x1_data,
const SPARSE_INDEX_TYPE_t[:] x1_indices,
const SPARSE_INDEX_TYPE_t[:] x1_indptr,
const {{INPUT_DTYPE_t}}* x2_data,
const SPARSE_INDEX_TYPE_t[:] x2_indices,
const SPARSE_INDEX_TYPE_t[:] x2_indptr,
const ITYPE_t size,
DTYPE_t[:, ::1] D,
) nogil except -1
cdef DTYPE_t _rdist_to_dist(self, {{INPUT_DTYPE_t}} rdist) nogil except -1
cdef DTYPE_t _dist_to_rdist(self, {{INPUT_DTYPE_t}} dist) nogil except -1
{{endfor}}
|
