def zero_cols(self, col_idxs):
mask = big_bm(self.num_cols)
mask.set_all_ones()
mask.unset_bits(col_idxs)
for i in range(self.num_rows):
self.matrix[i].band(self.matrix[i], mask)
def __init__(self, num_rows, num_cols):
self.num_rows = num_rows
self.num_cols = num_cols
self.matrix = []
for i in range(num_rows):
self.matrix.append(big_bm(num_cols))
