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1"Implements ConstraintSet"
2import sys
3from collections import defaultdict, OrderedDict
4from itertools import chain
5import numpy as np
6from ..keydict import KeySet, KeyDict
7from ..small_scripts import try_str_without
8from ..repr_conventions import ReprMixin
9from .single_equation import SingleEquationConstraint
12def add_meq_bounds(bounded, meq_bounded): #TODO: collapse with GP version?
13 "Iterates through meq_bounds until convergence"
14 still_alive = True
15 while still_alive:
16 still_alive = False # if no changes are made, the loop exits
17 for bound in list(meq_bounded):
18 if bound in bounded: # bound already exists
19 del meq_bounded[bound]
20 continue
21 for condition in meq_bounded[bound]:
22 if condition.issubset(bounded): # bound's condition is met
23 del meq_bounded[bound]
24 bounded.add(bound)
25 still_alive = True
26 break
28def _sort_by_name_and_idx(var):
29 "return tuple for Variable sorting"
30 return (var.key.str_without(["units", "idx"]), var.key.idx or ())
32def _sort_constraints(item):
33 "return tuple for Constraint sorting"
34 label, constraint = item
35 return (not isinstance(constraint, SingleEquationConstraint),
36 bool(getattr(constraint, "lineage", None)), label)
38def sort_constraints_dict(iterable):
39 "Sort a dictionary of {k: constraint} and return its keys and values"
40 if sys.version_info >= (3, 7) or isinstance(iterable, OrderedDict):
41 return iterable.keys(), iterable.values()
42 items = sorted(list(iterable.items()), key=_sort_constraints)
43 return (item[0] for item in items), (item[1] for item in items)
45def flatiter(iterable, yield_if_hasattr=None):
46 "Yields contained constraints, optionally including constraintsets."
47 if isinstance(iterable, dict):
48 _, iterable = sort_constraints_dict(iterable)
49 for constraint in iterable:
50 if (not hasattr(constraint, "__iter__")
51 or (yield_if_hasattr
52 and hasattr(constraint, yield_if_hasattr))):
53 yield constraint
54 else:
55 try: # numpy array
56 yield from constraint.flat
57 except TypeError: # ConstrainSet
58 yield from constraint.flat(yield_if_hasattr)
59 except AttributeError: # probably a list or dict
60 yield from flatiter(constraint, yield_if_hasattr)
63class ConstraintSet(list, ReprMixin):
64 "Recursive container for ConstraintSets and Inequalities"
65 unique_varkeys, idxlookup = frozenset(), {}
66 _name_collision_varkeys = None
67 _varkeys = None
69 def __init__(self, constraints, substitutions=None, *, bonusvks=None): # pylint: disable=too-many-branches,too-many-statements
70 if isinstance(constraints, dict):
71 keys, constraints = sort_constraints_dict(constraints)
72 self.idxlookup = {k: i for i, k in enumerate(keys)}
73 elif isinstance(constraints, ConstraintSet):
74 constraints = [constraints] # put it one level down
75 list.__init__(self, constraints)
76 self.vks = set(self.unique_varkeys)
77 self.substitutions = KeyDict({k: k.value for k in self.unique_varkeys
78 if "value" in k.descr})
79 self.substitutions.vks = self.vks
80 self.bounded, self.meq_bounded = set(), defaultdict(set)
81 for i, constraint in enumerate(self):
82 if hasattr(constraint, "vks"):
83 self._update(constraint)
84 elif not (hasattr(constraint, "as_hmapslt1")
85 or hasattr(constraint, "as_gpconstr")):
86 try:
87 for subconstraint in flatiter(constraint, "vks"):
88 self._update(subconstraint)
89 except Exception as e:
90 raise badelement(self, i, constraint) from e
91 elif isinstance(constraint, ConstraintSet):
92 raise badelement(self, i, constraint,
93 " It had not yet been initialized!")
94 if bonusvks:
95 self.vks.update(bonusvks)
96 if substitutions:
97 self.substitutions.update(substitutions)
98 for key in self.vks:
99 if key not in self.substitutions:
100 if key.veckey is None or key.veckey not in self.substitutions:
101 continue
102 if np.isnan(self.substitutions[key.veckey][key.idx]):
103 continue
104 self.bounded.add((key, "upper"))
105 self.bounded.add((key, "lower"))
106 if key.value is not None and not key.constant:
107 del key.descr["value"]
108 if key.veckey and key.veckey.value is not None:
109 del key.veckey.descr["value"]
110 add_meq_bounds(self.bounded, self.meq_bounded)
112 def _update(self, constraint):
113 "Update parameters with a given constraint"
114 self.vks.update(constraint.vks)
115 if hasattr(constraint, "substitutions"):
116 self.substitutions.update(constraint.substitutions)
117 else:
118 self.substitutions.update({k: k.value \
119 for k in constraint.vks if "value" in k.descr})
120 self.bounded.update(constraint.bounded)
121 for bound, solutionset in constraint.meq_bounded.items():
122 self.meq_bounded[bound].update(solutionset)
124 def __getitem__(self, key):
125 if key in self.idxlookup:
126 key = self.idxlookup[key]
127 if isinstance(key, int):
128 return list.__getitem__(self, key)
129 return self._choosevar(key, self.variables_byname(key))
131 def _choosevar(self, key, variables):
132 if not variables:
133 raise KeyError(key)
134 firstvar, *othervars = variables
135 veckey = firstvar.key.veckey
136 if veckey is None or any(v.key.veckey != veckey for v in othervars):
137 if not othervars:
138 return firstvar
139 raise ValueError("multiple variables are called '%s'; show them"
140 " with `.variables_byname('%s')`" % (key, key))
141 from ..nomials import NomialArray # all one vector!
142 arr = NomialArray(np.full(veckey.shape, np.nan, dtype="object"))
143 for v in variables:
144 arr[v.key.idx] = v
145 arr.key = veckey
146 return arr
148 def variables_byname(self, key):
149 "Get all variables with a given name"
150 from ..nomials import Variable
151 return sorted([Variable(k) for k in self.varkeys[key]],
152 key=_sort_by_name_and_idx)
154 @property
155 def varkeys(self):
156 "The NomialData's varkeys, created when necessary for a substitution."
157 if self._varkeys is None:
158 self._varkeys = KeySet(self.vks)
159 return self._varkeys
161 def constrained_varkeys(self):
162 "Return all varkeys in non-ConstraintSet constraints"
163 return self.vks - self.unique_varkeys
165 flat = flatiter
167 def as_hmapslt1(self, subs):
168 "Yields hmaps<=1 from self.flat()"
169 yield from chain(*(c.as_hmapslt1(subs)
170 for c in flatiter(self,
171 yield_if_hasattr="as_hmapslt1")))
173 def process_result(self, result):
174 """Does arbitrary computation / manipulation of a program's result
176 There's no guarantee what order different constraints will process
177 results in, so any changes made to the program's result should be
178 careful not to step on other constraint's toes.
180 Potential Uses
181 --------------
182 - check that an inequality was tight
183 - add values computed from solved variables
185 """
186 for constraint in self.flat(yield_if_hasattr="process_result"):
187 if hasattr(constraint, "process_result"):
188 constraint.process_result(result)
189 evalfn_vars = {v.veckey or v for v in self.unique_varkeys
190 if v.evalfn and v not in result["variables"]}
191 for v in evalfn_vars:
192 val = v.evalfn(result["variables"])
193 result["variables"][v] = result["freevariables"][v] = val
195 def __repr__(self):
196 "Returns namespaced string."
197 if not self:
198 return "<gpkit.%s object>" % self.__class__.__name__
199 return ("<gpkit.%s object containing %i top-level constraint(s)"
200 " and %i variable(s)>" % (self.__class__.__name__,
201 len(self), len(self.varkeys)))
203 def set_necessarylineage(self, clear=False):
204 "Returns the set of contained varkeys whose names are not unique"
205 if self._name_collision_varkeys is None:
206 self._name_collision_varkeys = {}
207 name_collisions = defaultdict(set)
208 for key in self.varkeys:
209 shortname = key.str_without(["lineage", "vec"])
210 if len(self.varkeys[shortname]) > 1:
211 name_collisions[shortname].add(key)
212 for varkeys in name_collisions.values():
213 min_namespaced = defaultdict(set)
214 for vk in varkeys:
215 *_, mineage = vk.lineagestr().split(".")
216 min_namespaced[(mineage, 1)].add(vk)
217 while any(len(vks) > 1 for vks in min_namespaced.values()):
218 for key, vks in list(min_namespaced.items()):
219 if len(vks) <= 1:
220 continue
221 del min_namespaced[key]
222 mineage, idx = key
223 idx += 1
224 for vk in vks:
225 lineages = vk.lineagestr().split(".")
226 submineage = lineages[-idx] + "." + mineage
227 min_namespaced[(submineage, idx)].add(vk)
228 for (_, idx), vks in min_namespaced.items():
229 vk, = vks
230 self._name_collision_varkeys[vk] = idx
231 if clear:
232 for vk in self._name_collision_varkeys:
233 del vk.descr["necessarylineage"]
234 else:
235 for vk, idx in self._name_collision_varkeys.items():
236 vk.descr["necessarylineage"] = idx
238 def lines_without(self, excluded):
239 "Lines representation of a ConstraintSet."
240 excluded = frozenset(excluded)
241 root, rootlines = "root" not in excluded, []
242 if root:
243 excluded = excluded.union(["root"])
244 if "unnecessary lineage" in excluded:
245 self.set_necessarylineage()
246 if hasattr(self, "_rootlines"):
247 rootlines = self._rootlines(excluded) # pylint: disable=no-member
248 lines = recursively_line(self, excluded)
249 indent = " " if getattr(self, "lineage", None) else ""
250 if root and "unnecessary lineage" in excluded:
251 indent += " "
252 self.set_necessarylineage(clear=True)
253 return rootlines + [(indent+line).rstrip() for line in lines]
255 def str_without(self, excluded=("unnecessary lineage", "units")):
256 "String representation of a ConstraintSet."
257 return "\n".join(self.lines_without(excluded))
259 def latex(self, excluded=("units",)):
260 "LaTeX representation of a ConstraintSet."
261 lines = []
262 root = "root" not in excluded
263 if root:
264 excluded += ("root",)
265 lines.append("\\begin{array}{ll} \\text{}")
266 if hasattr(self, "_rootlatex"):
267 lines.append(self._rootlatex(excluded)) # pylint: disable=no-member
268 for constraint in self:
269 cstr = try_str_without(constraint, excluded, latex=True)
270 if cstr[:6] != " & ": # require indentation
271 cstr = " & " + cstr + " \\\\"
272 lines.append(cstr)
273 if root:
274 lines.append("\\end{array}")
275 return "\n".join(lines)
277 def as_view(self):
278 "Return a ConstraintSetView of this ConstraintSet."
279 return ConstraintSetView(self)
281def recursively_line(iterable, excluded):
282 "Generates lines in a recursive tree-like fashion, the better to indent."
283 named_constraints = {}
284 if isinstance(iterable, dict):
285 keys, iterable = sort_constraints_dict(iterable)
286 named_constraints = dict(enumerate(keys))
287 elif hasattr(iterable, "idxlookup"):
288 named_constraints = {i: k for k, i in iterable.idxlookup.items()}
289 lines = []
290 for i, constraint in enumerate(iterable):
291 if hasattr(constraint, "lines_without"):
292 clines = constraint.lines_without(excluded)
293 elif not hasattr(constraint, "__iter__"):
294 clines = try_str_without(constraint, excluded).split("\n")
295 elif iterable is constraint:
296 clines = ["(constraint contained itself)"]
297 else:
298 clines = recursively_line(constraint, excluded)
299 if (getattr(constraint, "lineage", None)
300 and isinstance(constraint, ConstraintSet)):
301 name, num = constraint.lineage[-1]
302 if not any(clines):
303 clines = [" " + "(no constraints)"] # named model indent
304 if lines:
305 lines.append("")
306 lines.append(name if not num else name + str(num))
307 elif "constraint names" not in excluded and i in named_constraints:
308 lines.append("\"%s\":" % named_constraints[i])
309 clines = [" " + line for line in clines] # named constraint indent
310 lines.extend(clines)
311 return lines
314class ConstraintSetView:
315 "Class to access particular views on a set's variables"
317 def __init__(self, constraintset, index=()):
318 self.constraintset = constraintset
319 try:
320 self.index = tuple(index)
321 except TypeError: # probably not iterable
322 self.index = (index,)
324 def __getitem__(self, index):
325 "Appends the index to its own and returns a new view."
326 if not isinstance(index, tuple):
327 index = (index,)
328 # indexes are preprended to match Vectorize convention
329 return ConstraintSetView(self.constraintset, index + self.index)
331 def __getattr__(self, attr):
332 """Returns attribute from the base ConstraintSets
334 If it's a another ConstraintSet, return the matching View;
335 if it's an array, return it at the specified index;
336 otherwise, raise an error.
337 """
338 if not hasattr(self.constraintset, attr):
339 raise AttributeError("the underlying object lacks `.%s`." % attr)
341 value = getattr(self.constraintset, attr)
342 if isinstance(value, ConstraintSet):
343 return ConstraintSetView(value, self.index)
344 if not hasattr(value, "shape"):
345 raise ValueError("attribute %s with value %s did not have"
346 " a shape, so ConstraintSetView cannot"
347 " return an indexed view." % (attr, value))
348 index = self.index
349 newdims = len(value.shape) - len(self.index)
350 if newdims > 0: # indexes are put last to match Vectorize
351 index = (slice(None),)*newdims + index
352 return value[index]
356def badelement(cns, i, constraint, cause=""):
357 "Identify the bad element and raise a ValueError"
358 cause = cause if not isinstance(constraint, bool) else (
359 " Did the constraint list contain an accidental equality?")
360 if len(cns) == 1:
361 loc = "the only constraint"
362 elif i == 0:
363 loc = "at the start, before %s" % cns[i+1]
364 elif i == len(cns) - 1:
365 loc = "at the end, after %s" % cns[i-1]
366 else:
367 loc = "between %s and %s" % (cns[i-1], cns[i+1])
368 return ValueError("Invalid ConstraintSet element '%s' %s was %s.%s"
369 % (repr(constraint), type(constraint), loc, cause))