Current File : //lib/python3/dist-packages/scipy/optimize/_group_columns.py
"""
Pythran implementation of columns grouping for finite difference Jacobian
estimation. Used by ._numdiff.group_columns and based on the Cython version.
"""
import numpy as np
#pythran export group_dense(int, int, intc[:,:])
#pythran export group_dense(int, int, int[:,:])
def group_dense(m, n, A):
B = A.T # Transposed view for convenience.
# FIXME: use np.full once pythran supports it
groups = -np.ones(n, dtype=np.intp)
current_group = 0
union = np.empty(m, dtype=np.intp)
# Loop through all the columns.
for i in range(n):
if groups[i] >= 0: # A group was already assigned.
continue
groups[i] = current_group
all_grouped = True
union[:] = B[i] # Here we store the union of grouped columns.
for j in range(groups.shape[0]):
if groups[j] < 0:
all_grouped = False
else:
continue
# Determine if j-th column intersects with the union.
intersect = False
for k in range(m):
if union[k] > 0 and B[j, k] > 0:
intersect = True
break
# If not, add it to the union and assign the group to it.
if not intersect:
union += B[j]
groups[j] = current_group
if all_grouped:
break
current_group += 1
return groups
#pythran export group_sparse(int, int, intc[], intc[])
#pythran export group_sparse(int, int, int[], int[])
#pythran export group_sparse(int, int, intc[::], intc[::])
#pythran export group_sparse(int, int, int[::], int[::])
def group_sparse(m, n, indices, indptr):
groups = -np.ones(n, dtype=np.intp)
current_group = 0
union = np.empty(m, dtype=np.intp)
for i in range(n):
if groups[i] >= 0:
continue
groups[i] = current_group
all_grouped = True
union.fill(0)
for k in range(indptr[i], indptr[i + 1]):
union[indices[k]] = 1
for j in range(groups.shape[0]):
if groups[j] < 0:
all_grouped = False
else:
continue
intersect = False
for k in range(indptr[j], indptr[j + 1]):
if union[indices[k]] == 1:
intersect = True
break
if not intersect:
for k in range(indptr[j], indptr[j + 1]):
union[indices[k]] = 1
groups[j] = current_group
if all_grouped:
break
current_group += 1
return groups
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