x0 initialization with str keys fails.

[1ozturkbe]

It's looking for a Varkey, but gets str instead. Needs something like substitutions.update.

Beginning signomial solve.
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-6-dbbd52c503f3> in <module>()
----> 1 sol = m.penalty_ccp_solve(verbosity=2, mutategp=False, x0=x0)

c:\users\berk\dropbox (mit)\mit graduate school\code\gpkit\gpkit\constraints\prog_factories.pyc in solvefn(self, solver, verbosity, skipsweepfailures, **kwargs)
    122         else:
    123             self.program, progsolve = genfunction(self)
--> 124             result = progsolve(solver, verbosity, **kwargs)
    125             solution.append(result)
    126         solution.program = self.program

c:\users\berk\dropbox (mit)\mit graduate school\code\gpkit\gpkit\constraints\sgp.pyc in penalty_ccp_solve(self, solver, verbosity, x0, reltol, iteration_limit, mutategp, exp, **kwargs)
    193         self.result = relaxed_model.localsolve(solver, verbosity,
    194                                                x0, reltol, iteration_limit,
--> 195                                                mutategp, **kwargs)
    196         self.gps = relaxed_model.gps
    197         return self.result

c:\users\berk\dropbox (mit)\mit graduate school\code\gpkit\gpkit\constraints\sgp.pyc in localsolve(self, solver, verbosity, x0, reltol, iteration_limit, mutategp, **kwargs)
    120         mutategp = mutategp and not self.externalfns
    121         if x0 and not mutategp:
--> 122             self._gp = self.init_gp(self.substitutions, x0)
    123         slackvar = Variable()
    124         prevcost, cost, rel_improvement = None, None, None

c:\users\berk\dropbox (mit)\mit graduate school\code\gpkit\gpkit\constraints\sgp.pyc in init_gp(self, substitutions, x0)
    218         "Generates a simplified GP representation for later modification"
    219         gpconstrs, self._spconstrs, self._approx_lt, approx_gt = [], [], [], []
--> 220         x0 = self._fill_x0(x0)
    221         for cs in self.flat():
    222             try:

c:\users\berk\dropbox (mit)\mit graduate school\code\gpkit\gpkit\constraints\sgp.pyc in _fill_x0(self, x0)
    206     def _fill_x0(self, x0):
    207         "Returns a copy of x0 with subsitutions added."
--> 208         x0 = KeyDict(x0) if x0 else KeyDict()
    209         for key in self.varkeys:
    210             if key in x0:

c:\users\berk\dropbox (mit)\mit graduate school\code\gpkit\gpkit\keydict.pyc in __init__(self, *args, **kwargs)
     69         self.logged_gets = set()
     70         self.owned = set()
---> 71         self.update(*args, **kwargs)
     72
     73     def get(self, key, alternative=KeyError):

c:\users\berk\dropbox (mit)\mit graduate school\code\gpkit\gpkit\keydict.pyc in update(self, *args, **kwargs)
     94         else:
     95             for k, v in dict(*args, **kwargs).items():
---> 96                 self[k] = v
     97
     98     def parse_and_index(self, key):

c:\users\berk\dropbox (mit)\mit graduate school\code\gpkit\gpkit\keydict.pyc in __setitem__(self, key, value)
    210             value = value.value  # substitute constant monomials
    211         if isinstance(value, Quantity):
--> 212             value = value.to(key.units or "dimensionless").magnitude
    213         if idx:
    214             if is_sweepvar(value):

AttributeError: 'str' object has no attribute 'units'