def matmul(a: AbstractMatrix, b: Constant, tr_a=False, tr_b=False):
_assert_composable(a, b, tr_a=tr_a, tr_b=tr_b)
a = _tr(a, tr_a)
b = _tr(b, tr_b)
return LowRank(
B.expand_dims(B.sum(a, axis=1), axis=1),
B.ones(B.dtype(b), b.cols, 1),
B.fill_diag(b.const, 1),
)
def constant_to_lowrank(a):
dtype = B.dtype(a)
rows, cols = B.shape(a)
middle = B.fill_diag(a.const, 1)
if rows == cols:
return LowRank(B.ones(dtype, rows, 1), middle=middle)
else:
return LowRank(B.ones(dtype, rows, 1),
B.ones(dtype, cols, 1),
middle=middle)
def eye(a: AbstractMatrix):
assert_square(
a, "Can only construct identity matrices from square matrices.")
return B.fill_diag(B.one(a), B.shape(a)[0])
def test_fill_diag():
approx(B.fill_diag(2, 3), np.diag(np.array([2, 2, 2])))