# cirq.is_diagonal¶

cirq.is_diagonal(matrix: numpy.ndarray, *, atol: float = 1e-08) → bool[source]

Determines if a matrix is a approximately diagonal.

A matrix is diagonal if i!=j implies m[i,j]==0.

Parameters
• matrix – The matrix to check.

• atol – The per-matrix-entry absolute tolerance on equality.

Returns

Whether the matrix is diagonal within the given tolerance.