oineus.is_reduced

oineus.is_reduced(a)

Check whether a Z_2 boundary matrix is reduced.

A column is treated as nonzero in row i iff a[i, col] % 2 == 1, so any integer dtype with mod-2 semantics works (binary 0/1 matrices, or unreduced count matrices). Returns True iff every nonzero column has a distinct lowest-1 row index, which is the definition of a reduced matrix in the standard persistence reduction.

Parameters:

a – 2D array-like with .shape[1] columns and integer entries.

Returns:

True if the matrix is reduced.

Return type:

bool