straindesign.indicatorConstraints
=================================

.. py:module:: straindesign.indicatorConstraints

.. autoapi-nested-parse::

   Class for indicator contraints (IndicatorConstraints)





Module Contents
---------------

.. py:class:: IndicatorConstraints(binv, A, b, sense, indicval)

   A class for storing indicator contraints

   This class is a container for indicator constraints. Indicator constraints are used to link the fulfillment
   of a constraint to an indicating variable. For instance the indicator constraint:
   z = 1 -> 2*d - 1*e <= 3
   can be described as:
   If z=1, then 2*d - 1*e <= 3
   An alternative formulation of this association is possible with a bigM constraint:
   2*d - 1*e - z*M <= 3, with M = very large
   The constraint z = 0 -> 2*d - 1*e <= 3 would translate to 2*d - 1*e + z*M <= 3 + M
   Generally, indicator constraints are preferred over bigM, because they provide better numerical stability.
   However, not all solvers support indicator constraints

   Indicator constraints have the form:
   x_binv = indicval -> a * x <sense> b
   e.g.,: x_35 = 1 -> 2 * x_2 + 3 *x_3 'L' 6
                                       (<=)
   This class contains a set of indicator constraints:
   x_binv_1 = indicval_1 -> A_1 * x <sense_1> b_1
   x_binv_2 = indicval_2 -> A_2 * x <sense_2> b_2
   ...

   .. rubric:: Example

   ic = IndicatorConstraints(binv, A, b, sense, indicval)

   :param binv: (e.g.: [25, 27, 30])
                The index of the binary, indicating variables (indicators) for all indicator constraints.
                Integers are allowed ot occur more than once.
   :type binv: list of int
   :param A: Coefficient vectors for all indicator constraints, stored in one matrix, whereas
             each row is used in one indicator constraint.
             (num_columns = number of variables, num_rows = number of indicator constraints)
   :type A: sparse.csr_matrix
   :param b: Right hand sides of all indicator constraints. (e.g.: [0.1, 2.0, 3])
   :type b: list of float
   :param sense: (In)equality signs for all indicator constraints.
                 'L'ess or equal, 'E'qual or, 'G'reater or equal (e.g.: 'EEGLGLGE')
   :type sense: str
   :param indicval: Indicator values for all indicator constraints. Which value of the indicator
                    enforces the constraint, 0 or 1? (e.g., 0001010110)
   :type indicval: list of int

   :returns: An object of the IndicatorConstraints class to pass indicator constraints.
   :rtype: (IndicatorConstraints)