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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 name_collision_varkeys(self):
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 key for key in self.varkeys
208 if len(self.varkeys[key.str_without(["lineage", "vec"])]) > 1}
209 return self._name_collision_varkeys
211 def lines_without(self, excluded):
212 "Lines representation of a ConstraintSet."
213 excluded = frozenset(excluded)
214 root, rootlines = "root" not in excluded, []
215 if root:
216 excluded = excluded.union(["root"])
217 if "unnecessary lineage" in excluded:
218 for key in self.name_collision_varkeys():
219 key.descr["necessarylineage"] = True
220 if hasattr(self, "_rootlines"):
221 rootlines = self._rootlines(excluded) # pylint: disable=no-member
222 lines = recursively_line(self, excluded)
223 indent = " " if getattr(self, "lineage", None) else ""
224 if root and "unnecessary lineage" in excluded:
225 indent += " "
226 for key in self.name_collision_varkeys():
227 del key.descr["necessarylineage"]
228 return rootlines + [(indent+line).rstrip() for line in lines]
230 def str_without(self, excluded=("unnecessary lineage", "units")):
231 "String representation of a ConstraintSet."
232 return "\n".join(self.lines_without(excluded))
234 def latex(self, excluded=("units",)):
235 "LaTeX representation of a ConstraintSet."
236 lines = []
237 root = "root" not in excluded
238 if root:
239 excluded += ("root",)
240 lines.append("\\begin{array}{ll} \\text{}")
241 if hasattr(self, "_rootlatex"):
242 lines.append(self._rootlatex(excluded)) # pylint: disable=no-member
243 for constraint in self:
244 cstr = try_str_without(constraint, excluded, latex=True)
245 if cstr[:6] != " & ": # require indentation
246 cstr = " & " + cstr + " \\\\"
247 lines.append(cstr)
248 if root:
249 lines.append("\\end{array}")
250 return "\n".join(lines)
252 def as_view(self):
253 "Return a ConstraintSetView of this ConstraintSet."
254 return ConstraintSetView(self)
256def recursively_line(iterable, excluded):
257 "Generates lines in a recursive tree-like fashion, the better to indent."
258 named_constraints = {}
259 if isinstance(iterable, dict):
260 keys, iterable = sort_constraints_dict(iterable)
261 named_constraints = dict(enumerate(keys))
262 elif hasattr(iterable, "idxlookup"):
263 named_constraints = {i: k for k, i in iterable.idxlookup.items()}
264 lines = []
265 for i, constraint in enumerate(iterable):
266 if hasattr(constraint, "lines_without"):
267 clines = constraint.lines_without(excluded)
268 elif not hasattr(constraint, "__iter__"):
269 clines = try_str_without(constraint, excluded).split("\n")
270 elif iterable is constraint:
271 clines = ["(constraint contained itself)"]
272 else:
273 clines = recursively_line(constraint, excluded)
274 if (getattr(constraint, "lineage", None)
275 and isinstance(constraint, ConstraintSet)):
276 name, num = constraint.lineage[-1]
277 if not any(clines):
278 clines = [" " + "(no constraints)"] # named model indent
279 if lines:
280 lines.append("")
281 lines.append(name if not num else name + str(num))
282 elif "constraint names" not in excluded and i in named_constraints:
283 lines.append("\"%s\":" % named_constraints[i])
284 clines = [" " + line for line in clines] # named constraint indent
285 lines.extend(clines)
286 return lines
289class ConstraintSetView:
290 "Class to access particular views on a set's variables"
292 def __init__(self, constraintset, index=()):
293 self.constraintset = constraintset
294 try:
295 self.index = tuple(index)
296 except TypeError: # probably not iterable
297 self.index = (index,)
299 def __getitem__(self, index):
300 "Appends the index to its own and returns a new view."
301 if not isinstance(index, tuple):
302 index = (index,)
303 # indexes are preprended to match Vectorize convention
304 return ConstraintSetView(self.constraintset, index + self.index)
306 def __getattr__(self, attr):
307 """Returns attribute from the base ConstraintSets
309 If it's a another ConstraintSet, return the matching View;
310 if it's an array, return it at the specified index;
311 otherwise, raise an error.
312 """
313 if not hasattr(self.constraintset, attr):
314 raise AttributeError("the underlying object lacks `.%s`." % attr)
316 value = getattr(self.constraintset, attr)
317 if isinstance(value, ConstraintSet):
318 return ConstraintSetView(value, self.index)
319 if not hasattr(value, "shape"):
320 raise ValueError("attribute %s with value %s did not have"
321 " a shape, so ConstraintSetView cannot"
322 " return an indexed view." % (attr, value))
323 index = self.index
324 newdims = len(value.shape) - len(self.index)
325 if newdims > 0: # indexes are put last to match Vectorize
326 index = (slice(None),)*newdims + index
327 return value[index]
331def badelement(cns, i, constraint, cause=""):
332 "Identify the bad element and raise a ValueError"
333 cause = cause if not isinstance(constraint, bool) else (
334 " Did the constraint list contain an accidental equality?")
335 if len(cns) == 1:
336 loc = "the only constraint"
337 elif i == 0:
338 loc = "at the start, before %s" % cns[i+1]
339 elif i == len(cns) - 1:
340 loc = "at the end, after %s" % cns[i-1]
341 else:
342 loc = "between %s and %s" % (cns[i-1], cns[i+1])
343 return ValueError("Invalid ConstraintSet element '%s' %s was %s.%s"
344 % (repr(constraint), type(constraint), loc, cause))