1"Implement CostedConstraintSet" 

2import numpy as np 

3from .set import ConstraintSet 

4from ..small_scripts import maybe_flatten 

5from ..repr_conventions import lineagestr 

6 

7 

8class CostedConstraintSet(ConstraintSet): 

9 """A ConstraintSet with a cost 

10 

11 Arguments 

12 --------- 

13 cost : gpkit.Posynomial 

14 constraints : Iterable 

15 substitutions : dict 

16 """ 

17 lineage = None 

18 

19 def __init__(self, cost, constraints, substitutions=None): 

20 self.cost = maybe_flatten(cost) 

21 if isinstance(self.cost, np.ndarray): # if it's still a vector 

22 raise ValueError("Cost must be scalar, not the vector %s." % cost) 

23 subs = {k: k.value for k in self.cost.varkeys if "value" in k.descr} 

24 if substitutions: 

25 subs.update(substitutions) 

26 ConstraintSet.__init__(self, constraints, subs) 

27 self.varkeys.update(self.cost.varkeys) 

28 

29 def constrained_varkeys(self): 

30 "Return all varkeys in the cost and non-ConstraintSet constraints" 

31 constrained_varkeys = ConstraintSet.constrained_varkeys(self) 

32 constrained_varkeys.update(self.cost.varkeys) 

33 return constrained_varkeys 

34 

35 def _rootlines(self, excluded=()): 

36 "String showing cost, to be used when this is the top constraint" 

37 if self.cost.varkeys: 

38 description = ["", "Cost Function", "-------------", 

39 " %s" % self.cost.str_without(excluded), 

40 "", "Constraints", "-----------"] 

41 else: # don't print the cost if it's a constant 

42 description = ["", "Constraints", "-----------"] 

43 if self.lineage: 

44 fullname = lineagestr(self) 

45 description = [fullname, "="*len(fullname)] + description 

46 return description 

47 

48 def _rootlatex(self, excluded=()): 

49 "Latex showing cost, to be used when this is the top constraint" 

50 return "\n".join(["\\text{minimize}", 

51 " & %s \\\\" % self.cost.latex(excluded), 

52 "\\text{subject to}"])