Source Code for Module paramz.core.constrainable

  1  #=============================================================================== 
  2  # Copyright (c) 2015, Max Zwiessele 
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 29  #=============================================================================== 
 30  import numpy as np 
 31  from .indexable import Indexable 
 32  from ..transformations import Transformation,Logexp, NegativeLogexp, Logistic, __fixed__, FIXED, UNFIXED 
 33   
 34 -class Constrainable(Indexable): 
 35 -    def __init__(self, name, default_constraint=None, *a, **kw): 
 36          super(Constrainable, self).__init__(name=name) 
 37          self._default_constraint_ = default_constraint 
 38          from .index_operations import ParameterIndexOperations 
 39          self.add_index_operation('constraints', ParameterIndexOperations()) 
 40          if self._default_constraint_ is not None: 
 41              self.constrain(self._default_constraint_) 
 42   
 43  #    def __setstate__(self, state): 
 44  #        super(Constrainable, self).__setstate__(state) 
 45  #         #from .index_operations import ParameterIndexOperations 
 46  #         #self.add_index_operation('constraints', ParameterIndexOperations()) 
 47  #         #self._index_operations['constraints'] = self.constraints 
 48   
 49      #=========================================================================== 
 50      # Fixing Parameters: 
 51      #=========================================================================== 
 52 -    def constrain_fixed(self, value=None, warning=True, trigger_parent=True): 
 53          """ 
 54          Constrain this parameter to be fixed to the current value it carries. 
 55   
 56          This does not override the previous constraints, so unfixing will 
 57          restore the constraint set before fixing. 
 58   
 59          :param warning: print a warning for overwriting constraints. 
 60          """ 
 61          if value is not None: 
 62              self[:] = value 
 63   
 64          #index = self.unconstrain() 
 65          index = self._add_to_index_operations(self.constraints, np.empty(0), __fixed__, warning) 
 66          self._highest_parent_._set_fixed(self, index) 
 67          self.notify_observers(self, None if trigger_parent else -np.inf) 
 68          return index 
 69      fix = constrain_fixed 
 70   
 71 -    def unconstrain_fixed(self): 
 72          """ 
 73          This parameter will no longer be fixed. 
 74   
 75          If there was a constraint on this parameter when fixing it, 
 76          it will be constraint with that previous constraint. 
 77          """ 
 78          unconstrained = self.unconstrain(__fixed__) 
 79          self._highest_parent_._set_unfixed(self, unconstrained) 
 80          #if self._default_constraint_ is not None: 
 81          #    return self.constrain(self._default_constraint_) 
 82          return unconstrained 
 83      unfix = unconstrain_fixed 
 84   
 85 -    def _ensure_fixes(self): 
 86          # Ensure that the fixes array is set: 
 87          # Parameterized: ones(self.size) 
 88          # Param: ones(self._realsize_ 
 89          if (not hasattr(self, "_fixes_")) or (self._fixes_ is None) or (self._fixes_.size != self.size): 
 90              self._fixes_ = np.ones(self.size, dtype=bool) 
 91              self._fixes_[self.constraints[__fixed__]] = FIXED 
 92   
 93   
 94 -    def _set_fixed(self, param, index): 
 95          self._ensure_fixes() 
 96          offset = self._offset_for(param) 
 97          self._fixes_[index+offset] = FIXED 
 98          if np.all(self._fixes_): self._fixes_ = None  # ==UNFIXED 
 99   
100 -    def _set_unfixed(self, param, index): 
101          self._ensure_fixes() 
102          offset = self._offset_for(param) 
103          self._fixes_[index+offset] = UNFIXED 
104          if np.all(self._fixes_): self._fixes_ = None  # ==UNFIXED 
105   
106 -    def _connect_fixes(self): 
107          fixed_indices = self.constraints[__fixed__] 
108          if fixed_indices.size > 0: 
109              self._ensure_fixes() 
110              self._fixes_[:] = UNFIXED 
111              self._fixes_[fixed_indices] = FIXED 
112          else: 
113              self._fixes_ = None 
114              del self.constraints[__fixed__] 
115   
116      #=========================================================================== 
117      # Convenience for fixed 
118      #=========================================================================== 
119 -    def _has_fixes(self): 
120          return self.constraints[__fixed__].size != 0 
121   
122      @property 
123 -    def is_fixed(self): 
124          for p in self.parameters: 
125              if not p.is_fixed: return False 
126          return True 
127   
128 -    def _get_original(self, param): 
129          # if advanced indexing is activated it happens that the array is a copy 
130          # you can retrieve the original param through this method, by passing 
131          # the copy here 
132          return self.parameters[param._parent_index_] 
133   
134          #=========================================================================== 
135      # Constrain operations -> done 
136      #=========================================================================== 
137   
138 -    def constrain(self, transform, warning=True, trigger_parent=True): 
139          """ 
140          :param transform: the :py:class:`paramz.transformations.Transformation` 
141                            to constrain the this parameter to. 
142          :param warning: print a warning if re-constraining parameters. 
143   
144          Constrain the parameter to the given 
145          :py:class:`paramz.transformations.Transformation`. 
146          """ 
147          if isinstance(transform, Transformation): 
148              self.param_array[...] = transform.initialize(self.param_array) 
149          elif transform == __fixed__: 
150              return self.fix(warning=warning, trigger_parent=trigger_parent) 
151          else: 
152              raise ValueError('Can only constrain with paramz.transformations.Transformation object') 
153          reconstrained = self.unconstrain() 
154          added = self._add_to_index_operations(self.constraints, reconstrained, transform, warning) 
155          self.trigger_update(trigger_parent) 
156          return added 
157   
158 -    def unconstrain(self, *transforms): 
159          """ 
160          :param transforms: The transformations to unconstrain from. 
161   
162          remove all :py:class:`paramz.transformations.Transformation` 
163          transformats of this parameter object. 
164          """ 
165          return self._remove_from_index_operations(self.constraints, transforms) 
166   
167 -    def constrain_positive(self, warning=True, trigger_parent=True): 
168          """ 
169          :param warning: print a warning if re-constraining parameters. 
170   
171          Constrain this parameter to the default positive constraint. 
172          """ 
173          self.constrain(Logexp(), warning=warning, trigger_parent=trigger_parent) 
174   
175 -    def constrain_negative(self, warning=True, trigger_parent=True): 
176          """ 
177          :param warning: print a warning if re-constraining parameters. 
178   
179          Constrain this parameter to the default negative constraint. 
180          """ 
181          self.constrain(NegativeLogexp(), warning=warning, trigger_parent=trigger_parent) 
182   
183 -    def constrain_bounded(self, lower, upper, warning=True, trigger_parent=True): 
184          """ 
185          :param lower, upper: the limits to bound this parameter to 
186          :param warning: print a warning if re-constraining parameters. 
187   
188          Constrain this parameter to lie within the given range. 
189          """ 
190          self.constrain(Logistic(lower, upper), warning=warning, trigger_parent=trigger_parent) 
191   
192 -    def unconstrain_positive(self): 
193          """ 
194          Remove positive constraint of this parameter. 
195          """ 
196          self.unconstrain(Logexp()) 
197   
198 -    def unconstrain_negative(self): 
199          """ 
200          Remove negative constraint of this parameter. 
201          """ 
202          self.unconstrain(NegativeLogexp()) 
203   
204 -    def unconstrain_bounded(self, lower, upper): 
205          """ 
206          :param lower, upper: the limits to unbound this parameter from 
207   
208          Remove (lower, upper) bounded constrain from this parameter/ 
209          """ 
210          self.unconstrain(Logistic(lower, upper)) 
211