Coverage for gpkit/constraints/set.py: 86%

1"Implements ConstraintSet"

2import sys

3from collections import defaultdict, OrderedDict

4from itertools import chain

5import numpy as np

6from ..keydict import KeySet, KeyDict

7from ..nomials import NomialArray

8from ..small_scripts import try_str_without

9from ..repr_conventions import ReprMixin

10from .single_equation import SingleEquationConstraint

11from ..nomials import Variable

14def add_meq_bounds(bounded, meq_bounded): #TODO: collapse with GP version?

15 "Iterates through meq_bounds until convergence"

16 still_alive = True

17 while still_alive:

18 still_alive = False # if no changes are made, the loop exits

19 for bound in list(meq_bounded):

20 if bound in bounded: # bound already exists

21 del meq_bounded[bound]

22 continue

23 for condition in meq_bounded[bound]:

24 if condition.issubset(bounded): # bound's condition is met

25 del meq_bounded[bound]

26 bounded.add(bound)

27 still_alive = True

28 break

30def _sort_by_name_and_idx(var):

31 "return tuple for Variable sorting"

32 return (var.key.str_without(["units", "idx"]), var.key.idx or ())

34def _sort_constraints(item):

35 "return tuple for Constraint sorting"

36 label, constraint = item

37 return (not isinstance(constraint, SingleEquationConstraint),

38 bool(getattr(constraint, "lineage", None)), label)

40def sort_constraints_dict(iterable):

41 "Sort a dictionary of {k: constraint} and return its keys and values"

42 if sys.version_info >= (3, 7) or isinstance(iterable, OrderedDict):

43 return iterable.keys(), iterable.values()

44 items = sorted(list(iterable.items()), key=_sort_constraints)

45 return (item[0] for item in items), (item[1] for item in items)

47def flatiter(iterable, yield_if_hasattr=None):

48 "Yields contained constraints, optionally including constraintsets."

49 if isinstance(iterable, dict):

50 _, iterable = sort_constraints_dict(iterable)

51 for constraint in iterable:

52 if (not hasattr(constraint, "__iter__")

53 or (yield_if_hasattr

54 and hasattr(constraint, yield_if_hasattr))):

55 yield constraint

56 else:

57 try: # numpy array

58 yield from constraint.flat

59 except TypeError: # ConstrainSet

60 yield from constraint.flat(yield_if_hasattr)

61 except AttributeError: # probably a list or dict

62 yield from flatiter(constraint, yield_if_hasattr)

65class ConstraintSet(list, ReprMixin): # pylint: disable=too-many-instance-attributes

66 "Recursive container for ConstraintSets and Inequalities"

67 unique_varkeys, idxlookup = frozenset(), {}

68 _name_collision_varkeys = None

69 _varkeys = None

70 _lineageset = False

72 def __init__(self, constraints, substitutions=None, *, bonusvks=None): # pylint: disable=too-many-branches,too-many-statements

73 if isinstance(constraints, dict):

74 keys, constraints = sort_constraints_dict(constraints)

75 self.idxlookup = {k: i for i, k in enumerate(keys)}

76 elif isinstance(constraints, ConstraintSet):

77 constraints = [constraints] # put it one level down

78 list.__init__(self, constraints)

79 self.vks = set(self.unique_varkeys)

80 self.substitutions = KeyDict({k: k.value for k in self.unique_varkeys

81 if "value" in k.descr})

82 self.substitutions.vks = self.vks

83 self.bounded, self.meq_bounded = set(), defaultdict(set)

84 for i, constraint in enumerate(self):

85 if hasattr(constraint, "vks"):

86 self._update(constraint)

87 elif not (hasattr(constraint, "as_hmapslt1")

88 or hasattr(constraint, "as_gpconstr")):

89 try:

90 for subconstraint in flatiter(constraint, "vks"):

91 self._update(subconstraint)

92 except Exception as e:

93 raise badelement(self, i, constraint) from e

94 elif isinstance(constraint, ConstraintSet):

95 raise badelement(self, i, constraint,

96 " It had not yet been initialized!")

97 if bonusvks:

98 self.vks.update(bonusvks)

99 if substitutions:

100 self.substitutions.update(substitutions)

101 for key in self.vks:

102 if key not in self.substitutions:

103 if key.veckey is None or key.veckey not in self.substitutions:

104 continue

105 if np.isnan(self.substitutions[key.veckey][key.idx]):

106 continue

107 self.bounded.add((key, "upper"))

108 self.bounded.add((key, "lower"))

109 if key.value is not None and not key.constant:

110 del key.descr["value"]

111 if key.veckey and key.veckey.value is not None:

112 del key.veckey.descr["value"]

113 add_meq_bounds(self.bounded, self.meq_bounded)

114

115 def _update(self, constraint):

116 "Update parameters with a given constraint"

117 self.vks.update(constraint.vks)

118 if hasattr(constraint, "substitutions"):

119 self.substitutions.update(constraint.substitutions)

120 else:

121 self.substitutions.update({k: k.value \

122 for k in constraint.vks if "value" in k.descr})

123 self.bounded.update(constraint.bounded)

124 for bound, solutionset in constraint.meq_bounded.items():

125 self.meq_bounded[bound].update(solutionset)

126

127 def __getitem__(self, key):

128 if key in self.idxlookup:

129 key = self.idxlookup[key]

130 if isinstance(key, int):

131 return list.__getitem__(self, key)

132 return self._choosevar(key, self.variables_byname(key))

133

134 def _choosevar(self, key, variables):

135 if not variables:

136 raise KeyError(key)

137 firstvar, *othervars = variables

138 veckey = firstvar.key.veckey

139 if veckey is None or any(v.key.veckey != veckey for v in othervars):

140 if not othervars:

141 return firstvar

142 raise ValueError(f"multiple variables are called '{key}'; show them"

143 f" with `.variables_byname('{key}')`")

144 arr = NomialArray(np.full(veckey.shape, np.nan, dtype="object"))

145 for v in variables:

146 arr[v.key.idx] = v

147 arr.key = veckey

148 return arr

149

150 def variables_byname(self, key):

151 "Get all variables with a given name"

152 return sorted([Variable(k) for k in self.varkeys[key]],

153 key=_sort_by_name_and_idx)

154

155 @property

156 def varkeys(self):

157 "The NomialData's varkeys, created when necessary for a substitution."

158 if self._varkeys is None:

159 self._varkeys = KeySet(self.vks)

160 return self._varkeys

161

162 def constrained_varkeys(self):

163 "Return all varkeys in non-ConstraintSet constraints"

164 return self.vks - self.unique_varkeys

165

166 flat = flatiter

167

168 def as_hmapslt1(self, subs):

169 "Yields hmaps<=1 from self.flat()"

170 yield from chain(*(c.as_hmapslt1(subs)

171 for c in flatiter(self,

172 yield_if_hasattr="as_hmapslt1")))

173

174 def process_result(self, result):

175 """Does arbitrary computation / manipulation of a program's result

176

177 There's no guarantee what order different constraints will process

178 results in, so any changes made to the program's result should be

179 careful not to step on other constraint's toes.

180

181 Potential Uses

182 --------------

183 - check that an inequality was tight

184 - add values computed from solved variables

185

186 """

187 for constraint in self.flat(yield_if_hasattr="process_result"):

188 if hasattr(constraint, "process_result"):

189 constraint.process_result(result)

190 evalfn_vars = {v.veckey or v for v in self.unique_varkeys

191 if v.evalfn and v not in result["variables"]}

192 for v in evalfn_vars:

193 val = v.evalfn(result["variables"])

194 result["variables"][v] = result["freevariables"][v] = val

195

196 def __repr__(self):

197 "Returns namespaced string."

198 if not self:

199 return f"<gpkit.{self.__class__.__name__} object>"

200 return (f"<gpkit.{self.__class__.__name__} object containing "

201 f"{len(self)} top-level constraint(s) and "

202 f"{len(self.varkeys)} variable(s)>")

203

204 def set_necessarylineage(self, clear=False): # pylint: disable=too-many-branches

205 "Returns the set of contained varkeys whose names are not unique"

206 if self._name_collision_varkeys is None:

207 self._name_collision_varkeys = {}

208 name_collisions = defaultdict(set)

209 for key in self.varkeys:

210 if hasattr(key, "key"):

211 if key.veckey and all(k.veckey == key.veckey

212 for k in self.varkeys[key.name]):

213 self._name_collision_varkeys[key] = 0

214 self._name_collision_varkeys[key.veckey] = 0

215 elif len(self.varkeys[key.name]) == 1:

216 self._name_collision_varkeys[key] = 0

217 else:

218 shortname = key.str_without(["lineage", "vec"])

219 if len(self.varkeys[shortname]) > 1:

220 name_collisions[shortname].add(key)

221 for varkeys in name_collisions.values():

222 min_namespaced = defaultdict(set)

223 for vk in varkeys:

224 *_, mineage = vk.lineagestr().split(".")

225 min_namespaced[(mineage, 1)].add(vk)

226 while any(len(vks) > 1 for vks in min_namespaced.values()):

227 for key, vks in list(min_namespaced.items()):

228 if len(vks) <= 1:

229 continue

230 del min_namespaced[key]

231 mineage, idx = key

232 idx += 1

233 for vk in vks:

234 lineages = vk.lineagestr().split(".")

235 submineage = lineages[-idx] + "." + mineage

236 min_namespaced[(submineage, idx)].add(vk)

237 for (_, idx), vks in min_namespaced.items():

238 vk, = vks

239 self._name_collision_varkeys[vk] = idx

240 if clear:

241 self._lineageset = False

242 for vk in self._name_collision_varkeys:

243 del vk.descr["necessarylineage"]

244 else:

245 self._lineageset = True

246 for vk, idx in self._name_collision_varkeys.items():

247 vk.descr["necessarylineage"] = idx

248

249 def lines_without(self, excluded):

250 "Lines representation of a ConstraintSet."

251 excluded = frozenset(excluded)

252 root, rootlines = "root" not in excluded, []

253 if root:

254 excluded = {"root"}.union(excluded)

255 self.set_necessarylineage()

256 if hasattr(self, "_rootlines"):

257 rootlines = self._rootlines(excluded) # pylint: disable=no-member

258 lines = recursively_line(self, excluded)

259 indent = " " if root or getattr(self, "lineage", None) else ""

260 if root:

261 self.set_necessarylineage(clear=True)

262 return rootlines + [(indent+line).rstrip() for line in lines]

263

264 def str_without(self, excluded=("units",)):

265 "String representation of a ConstraintSet."

266 return "\n".join(self.lines_without(excluded))

267

268 def latex(self, excluded=("units",)):

269 "LaTeX representation of a ConstraintSet."

270 lines = []

271 root = "root" not in excluded

272 if root:

273 excluded += ("root",)

274 lines.append("\\begin{array}{ll} \\text{}")

275 if hasattr(self, "_rootlatex"):

276 lines.append(self._rootlatex(excluded)) # pylint: disable=no-member

277 for constraint in self:

278 cstr = try_str_without(constraint, excluded, latex=True)

279 if cstr[:6] != " & ": # require indentation

280 cstr = " & " + cstr + " \\\\"

281 lines.append(cstr)

282 if root:

283 lines.append("\\end{array}")

284 return "\n".join(lines)

285

286 def as_view(self):

287 "Return a ConstraintSetView of this ConstraintSet."

288 return ConstraintSetView(self)

289

290def recursively_line(iterable, excluded):

291 "Generates lines in a recursive tree-like fashion, the better to indent."

292 named_constraints = {}

293 if isinstance(iterable, dict):

294 keys, iterable = sort_constraints_dict(iterable)

295 named_constraints = dict(enumerate(keys))

296 elif hasattr(iterable, "idxlookup"):

297 named_constraints = {i: k for k, i in iterable.idxlookup.items()}

298 lines = []

299 for i, constraint in enumerate(iterable):

300 if hasattr(constraint, "lines_without"):

301 clines = constraint.lines_without(excluded)

302 elif not hasattr(constraint, "__iter__"):

303 clines = try_str_without(constraint, excluded).split("\n")

304 elif iterable is constraint:

305 clines = ["(constraint contained itself)"]

306 else:

307 clines = recursively_line(constraint, excluded)

308 if (getattr(constraint, "lineage", None)

309 and isinstance(constraint, ConstraintSet)):

310 name, num = constraint.lineage[-1]

311 if not any(clines):

312 clines = [" " + "(no constraints)"] # named model indent

313 if lines:

314 lines.append("")

315 lines.append(name if not num else name + str(num))

316 elif "constraint names" not in excluded and i in named_constraints:

317 lines.append(f"\"{named_constraints[i]}\":")

318 clines = [" " + line for line in clines] # named constraint indent

319 lines.extend(clines)

320 return lines

321

322

323class ConstraintSetView:

324 "Class to access particular views on a set's variables"

325

326 def __init__(self, constraintset, index=()):

327 self.constraintset = constraintset

328 try:

329 self.index = tuple(index)

330 except TypeError: # probably not iterable

331 self.index = (index,)

332

333 def __getitem__(self, index):

334 "Appends the index to its own and returns a new view."

335 if not isinstance(index, tuple):

336 index = (index,)

337 # indexes are preprended to match Vectorize convention

338 return ConstraintSetView(self.constraintset, index + self.index)

339

340 def __getattr__(self, attr):

341 """Returns attribute from the base ConstraintSets

342

343 If it's a another ConstraintSet, return the matching View;

344 if it's an array, return it at the specified index;

345 otherwise, raise an error.

346 """

347 if not hasattr(self.constraintset, attr):

348 raise AttributeError(f"the underlying object lacks `.{attr}`.")

349

350 value = getattr(self.constraintset, attr)

351 if isinstance(value, ConstraintSet):

352 return ConstraintSetView(value, self.index)

353 if not hasattr(value, "shape"):

354 raise ValueError(

355 f"attribute {attr} with value {value} did not have a shape, "

356 "so ConstraintSetView cannot return an indexed view.")

357 index = self.index

358 newdims = len(value.shape) - len(self.index)

359 if newdims > 0: # indexes are put last to match Vectorize

360 index = (slice(None),)*newdims + index

361 return value[index]

362

363

364

365def badelement(cns, i, constraint, cause=""):

366 "Identify the bad element and raise a ValueError"

367 cause = cause if not isinstance(constraint, bool) else (

368 " Did the constraint list contain an accidental equality?")

369 if len(cns) == 1:

370 loc = "the only constraint"

371 elif i == 0:

372 loc = f"at the start, before {cns[i+1]}"

373 elif i == len(cns) - 1:

374 loc = f"at the end, after {cns[i-1]}"

375 else:

376 loc = f"between {cns[i-1]} and {cns[i+1]}"

377 return ValueError(f"Invalid ConstraintSet element '{constraint!r}' "

378 f"{type(constraint)} was {loc}.{cause}")