:py:mod:`cobra.sampling.core` ============================= .. py:module:: cobra.sampling.core .. autoapi-nested-parse:: Provide low-level sampling stepper functions and helpers. Module Contents --------------- Functions ~~~~~~~~~ .. autoapisummary:: cobra.sampling.core.step Attributes ~~~~~~~~~~ .. autoapisummary:: cobra.sampling.core.logger cobra.sampling.core.MAX_TRIES .. py:data:: logger .. py:data:: MAX_TRIES :value: 100 .. py:function:: step(sampler: cobra.sampling.hr_sampler.HRSampler, x: numpy.ndarray, delta: numpy.ndarray, fraction: Optional[float] = None, tries: int = 0) -> numpy.ndarray Sample a new feasible point from the point `x` in direction `delta`. This is the low-level sampling stepper for samplers derived from `HRSampler`. Currently, it's used by `ACHRSampler` and `OptGPSampler`. It's declared outside of the base sampling class to facilitate use of multiprocessing. :param sampler: The sampler to sample a step for. :type sampler: cobra.sampling.HRSampler :param x: A point in the sampling region. :type x: np.array :param delta: The direction to take the step in. :type delta: np.array :param fraction: A float controlling the part of alpha difference to contribute to the fraction of `delta` (default None). If None, alpha is obtained from a normal distribution. :type fraction: float, optional :param tries: Total number of tries (default 0). :type tries: int, optional :returns: The new numpy array obtained after a step of sampling. :rtype: np.array :raises RuntimeError: If `tries` exceeds `MAX_TRIES`.