verry.optimize.krawczyk#

verry.optimize.krawczyk(fun, x, fprime=None)#

Apply the Krawczyk test to the multivariate vector-valued function.

Parameters:
  • fun (Callable) – Function to find a root of.

  • x (IntervalMatrix) – Candidate set for which a root is expected to exist.

  • fprime (Callable | IntervalMatrix, optional) – Derivative of fun, or an image of x under the derivative (the default is jacobian(fun)).

Returns:

  • r0 (Literal[“EXISTS”, “NOTEXISTS”, “UNIQUE”, “UNKNOWN”])

  • r1 (IntervalMatrix | None) – If r0 is "EXISTS" or "UNIQUE", r1 is the set containing the root; otherwise, r1 is None.

Warning

fun must be a \(C^1\)-function on x. Futhermore, fun must neither be a constant nor contain conditional branches (cf. Common pitfalls).