Converts offers/bids to pwl functions and updates limits.

def _offbidToCase(self):
        """ Converts offers/bids to pwl functions and updates limits.
        """
        generators = [g for g in self.case.generators if not g.is_load]
        vLoads = [g for g in self.case.generators if g.is_load]

        # Convert offers into piecewise linear segments and update limits.
        for g in generators:
#            print "G: ", g.p_min, g.p_max, g.p_cost, g.pcost_model

            g.offers_to_pwl(self.offers)

#            print "GG:", g.p_min, g.p_max, g.p_cost, g.pcost_model

        for vl in vLoads:
#            print "L: ", vl.p_min, vl.p_max, vl.p_cost

            vl.bids_to_pwl(self.bids)

#            print "VL:", vl.p_min, vl.p_max, g.q_min, g.q_max, vl.p_cost

        # Move p_min and p_max limits out slightly to avoid problems with
        # lambdas caused by rounding errors when corner point of cost function
        # lies at exactly p_min or p_max.
        for g in generators: # Skip dispatchable loads.
            g.p_min -= 100 * self.violation
            g.p_max += 100 * self.violation