source: orange/orange/orngLookup.py @ 1:58e9b1033604

Revision 1:58e9b1033604, 3.3 KB checked in by tomazc <tomazc@…>, 11 years ago (diff)

prvi uvoz

Line 
1import orange, orngMisc
2
3def lookupFromBound(attribute, bound):
4    if not len(bound):
5        raise TypeError, "no bound attributes"
6    elif len(bound)<=3:
7        return apply([orange.ClassifierByLookupTable, orange.ClassifierByLookupTable2, orange.ClassifierByLookupTable3][len(bound)-1], [attribute] + list(bound))
8    else:
9        return None
10
11   
12def lookupFromFunction(attribute, bound, function):
13    """
14    Constructs ClassifierByExampleTable or ClassifierByLookupTable mirroring the given function
15    """
16    lookup = lookupFromBound(attribute, bound)
17    if lookup:
18        lookup.lookupTable = [orange.Value(attribute, function(attributes)) for attributes in orngMisc.LimitedCounter([len(attr.values) for attr in bound])]
19        return lookup
20    else:
21        examples = orange.ExampleTable(orange.Domain(bound, attribute))
22        for attributes in orngMisc.LimitedCounter([len(attr.values) for attr in dom.attributes]):
23            examples.append(orange.Example(dom, attributes + [function(attributes)]))
24        return orange.LookupLearner(examples)
25     
26
27def lookupFromExamples(examples, weight = 0, learnerForUnknown = None):
28    if len(examples.domain.attributes) <= 3:
29        lookup = lookupFromBound(examples.domain.classVar, examples.domain.attributes)
30        lookupTable = lookup.lookupTable
31        for example in examples:
32            ind = lookup.getindex(example)
33            if not lookupTable[ind].isSpecial() and (lookupTable[ind] <> example.getclass()):
34                break
35            lookupTable[ind] = example.getclass()
36        else:
37            return lookup
38
39        # there are ambiguities; a backup plan is ClassifierByExampleTable, let it deal with them
40        return orange.LookupLearner(examples, weight, learnerForUnknown = learnerForUnknown)
41
42    else:
43        return orange.LookupLearner(examples, weight, learnerForUnknown = learnerForUnknown)
44       
45       
46def printLookupFunction(func):
47    if isinstance(func, orange.Variable):
48        if not func.getValueFrom:
49            raise TypeError, "attribute '%s' does not have an associated function" % func.name
50        else:
51            func = func.getValueFrom
52
53    outp = ""
54    if isinstance(func, orange.ClassifierByExampleTable):
55    # XXX This needs some polishing :-)
56        for i in func.sortedExamples:
57            outp += "%s\n" % i
58    else:
59        boundset = func.boundset()
60        for a in boundset:
61            outp += "%s\t" % a.name
62        outp += "%s\n" % func.classVar.name
63        outp += "------\t" * (len(boundset)+1) + "\n"
64       
65        lc = 0
66        if len(boundset)==1:
67            cnt = orngMisc.LimitedCounter([len(x.values)+1 for x in boundset])
68        else:
69            cnt = orngMisc.LimitedCounter([len(x.values) for x in boundset])
70        for ex in cnt:
71            for i in range(len(ex)):
72                if ex[i]<len(boundset[i].values):
73                    outp += "%s\t" % boundset[i].values[ex[i]]
74                else:
75                    outp += "?\t",
76            outp += "%s\n" % func.classVar.values[int(func.lookupTable[lc])]
77            lc += 1
78    return outp
79
80
81for tpe in [orange.ClassifierByLookupTable, orange.ClassifierByLookupTable2, orange.ClassifierByLookupTable3, orange.ClassifierByExampleTable]:
82    orange.setoutput(tpe, "tab", printLookupFunction)
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