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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.cset = self
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 self._varkeys = None
99 for key in self.vks:
100 if key not in self.substitutions:
101 if key.veckey is None or key.veckey not in self.substitutions:
102 continue
103 if np.isnan(self.substitutions[key.veckey][key.idx]):
104 continue
105 self.bounded.add((key, "upper"))
106 self.bounded.add((key, "lower"))
107 if key.value is not None and not key.constant:
108 del key.descr["value"]
109 if key.veckey and key.veckey.value is not None:
110 del key.veckey.descr["value"]
111 add_meq_bounds(self.bounded, self.meq_bounded)
113 def _update(self, constraint):
114 "Update parameters with a given constraint"
115 self.vks.update(constraint.vks)
116 if hasattr(constraint, "substitutions"):
117 self.substitutions.update(constraint.substitutions)
118 else:
119 self.substitutions.update({k: k.value \
120 for k in constraint.vks if "value" in k.descr})
121 self.bounded.update(constraint.bounded)
122 for bound, solutionset in constraint.meq_bounded.items():
123 self.meq_bounded[bound].update(solutionset)
125 def __getitem__(self, key):
126 if key in self.idxlookup:
127 key = self.idxlookup[key]
128 if isinstance(key, int):
129 return list.__getitem__(self, key)
130 return self._choosevar(key, self.variables_byname(key))
132 def _choosevar(self, key, variables):
133 if not variables:
134 raise KeyError(key)
135 firstvar, *othervars = variables
136 veckey = firstvar.key.veckey
137 if veckey is None or any(v.key.veckey != veckey for v in othervars):
138 if not othervars:
139 return firstvar
140 raise ValueError("multiple variables are called '%s'; show them"
141 " with `.variables_byname('%s')`" % (key, key))
142 from ..nomials import NomialArray # all one vector!
143 arr = NomialArray(np.full(veckey.shape, np.nan, dtype="object"))
144 for v in variables:
145 arr[v.key.idx] = v
146 arr.key = veckey
147 return arr
149 def variables_byname(self, key):
150 "Get all variables with a given name"
151 from ..nomials import Variable
152 return sorted([Variable(k) for k in self.varkeys[key]],
153 key=_sort_by_name_and_idx)
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
162 def constrained_varkeys(self):
163 "Return all varkeys in non-ConstraintSet constraints"
164 return self.vks - self.unique_varkeys
166 flat = flatiter
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")))
174 def process_result(self, result):
175 """Does arbitrary computation / manipulation of a program's result
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.
181 Potential Uses
182 --------------
183 - check that an inequality was tight
184 - add values computed from solved variables
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
196 def __repr__(self):
197 "Returns namespaced string."
198 if not self:
199 return "<gpkit.%s object>" % self.__class__.__name__
200 return ("<gpkit.%s object containing %i top-level constraint(s)"
201 " and %i variable(s)>" % (self.__class__.__name__,
202 len(self), len(self.varkeys)))
204 def name_collision_varkeys(self):
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 key for key in self.varkeys
209 if len(self.varkeys[key.str_without(["lineage", "vec"])]) > 1}
210 return self._name_collision_varkeys
212 def lines_without(self, excluded):
213 "Lines representation of a ConstraintSet."
214 excluded = frozenset(excluded)
215 root, rootlines = "root" not in excluded, []
216 if root:
217 excluded = excluded.union(["root"])
218 if "unnecessary lineage" in excluded:
219 for key in self.name_collision_varkeys():
220 key.descr["necessarylineage"] = True
221 if hasattr(self, "_rootlines"):
222 rootlines = self._rootlines(excluded) # pylint: disable=no-member
223 lines = recursively_line(self, excluded)
224 indent = " " if getattr(self, "lineage", None) else ""
225 if root and "unnecessary lineage" in excluded:
226 indent += " "
227 for key in self.name_collision_varkeys():
228 del key.descr["necessarylineage"]
229 return rootlines + [(indent+line).rstrip() for line in lines]
231 def str_without(self, excluded=("unnecessary lineage", "units")):
232 "String representation of a ConstraintSet."
233 return "\n".join(self.lines_without(excluded))
235 def latex(self, excluded=("units",)):
236 "LaTeX representation of a ConstraintSet."
237 lines = []
238 root = "root" not in excluded
239 if root:
240 excluded += ("root",)
241 lines.append("\\begin{array}{ll} \\text{}")
242 if hasattr(self, "_rootlatex"):
243 lines.append(self._rootlatex(excluded)) # pylint: disable=no-member
244 for constraint in self:
245 cstr = try_str_without(constraint, excluded, latex=True)
246 if cstr[:6] != " & ": # require indentation
247 cstr = " & " + cstr + " \\\\"
248 lines.append(cstr)
249 if root:
250 lines.append("\\end{array}")
251 return "\n".join(lines)
253 def as_view(self):
254 "Return a ConstraintSetView of this ConstraintSet."
255 return ConstraintSetView(self)
257def recursively_line(iterable, excluded):
258 "Generates lines in a recursive tree-like fashion, the better to indent."
259 named_constraints = {}
260 if isinstance(iterable, dict):
261 keys, iterable = sort_constraints_dict(iterable)
262 named_constraints = dict(enumerate(keys))
263 elif hasattr(iterable, "idxlookup"):
264 named_constraints = {i: k for k, i in iterable.idxlookup.items()}
265 lines = []
266 for i, constraint in enumerate(iterable):
267 if hasattr(constraint, "lines_without"):
268 clines = constraint.lines_without(excluded)
269 elif not hasattr(constraint, "__iter__"):
270 clines = try_str_without(constraint, excluded).split("\n")
271 elif iterable is constraint:
272 clines = ["(constraint contained itself)"]
273 else:
274 clines = recursively_line(constraint, excluded)
275 if (getattr(constraint, "lineage", None)
276 and isinstance(constraint, ConstraintSet)):
277 name, num = constraint.lineage[-1]
278 if not any(clines):
279 clines = [" " + "(no constraints)"] # named model indent
280 if lines:
281 lines.append("")
282 lines.append(name if not num else name + str(num))
283 elif "constraint names" not in excluded and i in named_constraints:
284 lines.append("\"%s\":" % named_constraints[i])
285 clines = [" " + line for line in clines] # named constraint indent
286 lines.extend(clines)
287 return lines
290class ConstraintSetView:
291 "Class to access particular views on a set's variables"
293 def __init__(self, constraintset, index=()):
294 self.constraintset = constraintset
295 try:
296 self.index = tuple(index)
297 except TypeError: # probably not iterable
298 self.index = (index,)
300 def __getitem__(self, index):
301 "Appends the index to its own and returns a new view."
302 if not isinstance(index, tuple):
303 index = (index,)
304 # indexes are preprended to match Vectorize convention
305 return ConstraintSetView(self.constraintset, index + self.index)
307 def __getattr__(self, attr):
308 """Returns attribute from the base ConstraintSets
310 If it's a another ConstraintSet, return the matching View;
311 if it's an array, return it at the specified index;
312 otherwise, raise an error.
313 """
314 if not hasattr(self.constraintset, attr):
315 raise AttributeError("the underlying object lacks `.%s`." % attr)
317 value = getattr(self.constraintset, attr)
318 if isinstance(value, ConstraintSet):
319 return ConstraintSetView(value, self.index)
320 if not hasattr(value, "shape"):
321 raise ValueError("attribute %s with value %s did not have"
322 " a shape, so ConstraintSetView cannot"
323 " return an indexed view." % (attr, value))
324 index = self.index
325 newdims = len(value.shape) - len(self.index)
326 if newdims > 0: # indexes are put last to match Vectorize
327 index = (slice(None),)*newdims + index
328 return value[index]
332def badelement(cns, i, constraint, cause=""):
333 "Identify the bad element and raise a ValueError"
334 cause = cause if not isinstance(constraint, bool) else (
335 " Did the constraint list contain an accidental equality?")
336 if len(cns) == 1:
337 loc = "the only constraint"
338 elif i == 0:
339 loc = "at the start, before %s" % cns[i+1]
340 elif i == len(cns) - 1:
341 loc = "at the end, after %s" % cns[i-1]
342 else:
343 loc = "between %s and %s" % (cns[i-1], cns[i+1])
344 return ValueError("Invalid ConstraintSet element '%s' %s was %s.%s"
345 % (repr(constraint), type(constraint), loc, cause))