# skfolio.utils.stats.is_positive_semidefinite ### skfolio.utils.stats.is_positive_semidefinite(x, \*, atol=0.0) Return True if the matrix is positive semidefinite within a tolerance. The caller must provide a finite, symmetric matrix. * **Parameters:** **x** *ndarray of shape (n, n)* : Matrix to check. **atol** *float, default=0.0* : Nonnegative absolute tolerance. Eigenvalues greater than or equal to `-atol` are accepted. * **Returns:** **value** *bool* : True if all eigenvalues are at least `-atol`, False otherwise. Singular matrices are accepted.