Mercurial > pylearn

annotate learner.py @ 12:ff4e551490f1

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Added LookupList type in lookup_list.py and used it to keep order of field names in Example in ArrayDataSet. Example is now just = LookupList.
author bengioy@esprit.iro.umontreal.ca
date Wed, 26 Mar 2008 18:21:57 -0400
parents 80bf5492e571
children 633453635d51
rev   line source
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2cd82666b9a7 Added statscollector and started writing dataset and learner.
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1
2cd82666b9a7 Added statscollector and started writing dataset and learner.
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2 from dataset import *
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3 from statscollector import *
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4
2cd82666b9a7 Added statscollector and started writing dataset and learner.
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5 class Learner(object):
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6 """Base class for learning algorithms, provides an interface
2cd82666b9a7 Added statscollector and started writing dataset and learner.
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7 that allows various algorithms to be applicable to generic learning
2cd82666b9a7 Added statscollector and started writing dataset and learner.
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8 algorithms.
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9
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80bf5492e571 Rewrote learner.py according to the specs in the wiki for learners.
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10 A Learner can be seen as a learning algorithm, a function that when
80bf5492e571 Rewrote learner.py according to the specs in the wiki for learners.
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11 applied to training data returns a learned function, an object that
80bf5492e571 Rewrote learner.py according to the specs in the wiki for learners.
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12 can be applied to other data and return some output data.
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13 """
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80bf5492e571 Rewrote learner.py according to the specs in the wiki for learners.
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15 def __init__(self):
80bf5492e571 Rewrote learner.py according to the specs in the wiki for learners.
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16 pass
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17
80bf5492e571 Rewrote learner.py according to the specs in the wiki for learners.
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18 def forget(self):
80bf5492e571 Rewrote learner.py according to the specs in the wiki for learners.
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19 """
80bf5492e571 Rewrote learner.py according to the specs in the wiki for learners.
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20 Reset the state of the learner to a blank slate, before seeing
80bf5492e571 Rewrote learner.py according to the specs in the wiki for learners.
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21 training data. The operation may be non-deterministic if the
80bf5492e571 Rewrote learner.py according to the specs in the wiki for learners.
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22 learner has a random number generator that is set to use a
80bf5492e571 Rewrote learner.py according to the specs in the wiki for learners.
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23 different seed each time it forget() is called.
80bf5492e571 Rewrote learner.py according to the specs in the wiki for learners.
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24 """
80bf5492e571 Rewrote learner.py according to the specs in the wiki for learners.
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25 raise NotImplementedError
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26
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27 def update(self,training_set):
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28 """
80bf5492e571 Rewrote learner.py according to the specs in the wiki for learners.
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29 Continue training a learner, with the evidence provided by the given training set.
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30 Hence update can be called multiple times. This is particularly useful in the
80bf5492e571 Rewrote learner.py according to the specs in the wiki for learners.
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31 on-line setting or the sequential (Bayesian or not) settings.
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32 The result is a function that can be applied on data, with the same
80bf5492e571 Rewrote learner.py according to the specs in the wiki for learners.
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33 semantics of the Learner.use method.
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34 """
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35 return self.use
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36
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37
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38 def __call__(self,training_set):
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39 """
80bf5492e571 Rewrote learner.py according to the specs in the wiki for learners.
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40 Train a learner from scratch using the provided training set,
80bf5492e571 Rewrote learner.py according to the specs in the wiki for learners.
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41 and return the learned function.
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42 """
80bf5492e571 Rewrote learner.py according to the specs in the wiki for learners.
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43 self.forget()
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44 return self.update(learning_task)
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46
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47 def use(self,input_dataset,output_fields=None):
80bf5492e571 Rewrote learner.py according to the specs in the wiki for learners.
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48 """Once a Learner has been trained by one or more call to 'update', it can
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49 be used with one or more calls to 'use'. The argument is a DataSet (possibly
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50 containing a single example) and the result is a DataSet of the same length.
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51 If output_fields is specified, it may be use to indicate which fields should
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52 be constructed in the output DataSet (for example ['output','classification_error']).
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53 """
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54 raise NotImplementedError