Fixed database typo and removed unnecessary class identifier.

venv/Lib/site-packages/scipy/sparse/spfuncs.py

@@ -0,0 +1,98 @@
+""" Functions that operate on sparse matrices
+"""
+
+__all__ = ['count_blocks','estimate_blocksize']
+
+from .csr import isspmatrix_csr, csr_matrix
+from .csc import isspmatrix_csc
+from ._sparsetools import csr_count_blocks
+
+
+def extract_diagonal(A):
+    raise NotImplementedError('use .diagonal() instead')
+
+#def extract_diagonal(A):
+#    """extract_diagonal(A) returns the main diagonal of A."""
+#    #TODO extract kth diagonal
+#    if isspmatrix_csr(A) or isspmatrix_csc(A):
+#        fn = getattr(sparsetools, A.format + "_diagonal")
+#        y = empty( min(A.shape), dtype=upcast(A.dtype) )
+#        fn(A.shape[0],A.shape[1],A.indptr,A.indices,A.data,y)
+#        return y
+#    elif isspmatrix_bsr(A):
+#        M,N = A.shape
+#        R,C = A.blocksize
+#        y = empty( min(M,N), dtype=upcast(A.dtype) )
+#        fn = sparsetools.bsr_diagonal(M//R, N//C, R, C, \
+#                A.indptr, A.indices, ravel(A.data), y)
+#        return y
+#    else:
+#        return extract_diagonal(csr_matrix(A))
+
+
+def estimate_blocksize(A,efficiency=0.7):
+    """Attempt to determine the blocksize of a sparse matrix
+
+    Returns a blocksize=(r,c) such that
+        - A.nnz / A.tobsr( (r,c) ).nnz > efficiency
+    """
+    if not (isspmatrix_csr(A) or isspmatrix_csc(A)):
+        A = csr_matrix(A)
+
+    if A.nnz == 0:
+        return (1,1)
+
+    if not 0 < efficiency < 1.0:
+        raise ValueError('efficiency must satisfy 0.0 < efficiency < 1.0')
+
+    high_efficiency = (1.0 + efficiency) / 2.0
+    nnz = float(A.nnz)
+    M,N = A.shape
+
+    if M % 2 == 0 and N % 2 == 0:
+        e22 = nnz / (4 * count_blocks(A,(2,2)))
+    else:
+        e22 = 0.0
+
+    if M % 3 == 0 and N % 3 == 0:
+        e33 = nnz / (9 * count_blocks(A,(3,3)))
+    else:
+        e33 = 0.0
+
+    if e22 > high_efficiency and e33 > high_efficiency:
+        e66 = nnz / (36 * count_blocks(A,(6,6)))
+        if e66 > efficiency:
+            return (6,6)
+        else:
+            return (3,3)
+    else:
+        if M % 4 == 0 and N % 4 == 0:
+            e44 = nnz / (16 * count_blocks(A,(4,4)))
+        else:
+            e44 = 0.0
+
+        if e44 > efficiency:
+            return (4,4)
+        elif e33 > efficiency:
+            return (3,3)
+        elif e22 > efficiency:
+            return (2,2)
+        else:
+            return (1,1)
+
+
+def count_blocks(A,blocksize):
+    """For a given blocksize=(r,c) count the number of occupied
+    blocks in a sparse matrix A
+    """
+    r,c = blocksize
+    if r < 1 or c < 1:
+        raise ValueError('r and c must be positive')
+
+    if isspmatrix_csr(A):
+        M,N = A.shape
+        return csr_count_blocks(M,N,r,c,A.indptr,A.indices)
+    elif isspmatrix_csc(A):
+        return count_blocks(A.T,(c,r))
+    else:
+        return count_blocks(csr_matrix(A),blocksize)