type ConfusionMatrix
source code
object --+
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ConfusionMatrix
The confusion matrix between a list of reference values and a
corresponding list of test values. Entry [r,t] of this matrix is a count of the number of times that
the reference value r corresponds to the test value
t. E.g.:
>>> ref = 'DET NN VB DET JJ NN NN IN DET NN'.split()
>>> test = 'DET VB VB DET NN NN NN IN DET NN'.split()
>>> cm = ConfusionMatrix(ref, test)
>>> print cm['NN', 'NN']
3
Note that the diagonal entries (Ri=Tj) of this matrix corresponds to correct values; and
the off-diagonal entries correspond to incorrect values.
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__init__(self,
reference,
test,
sort_by_count=False)
Construct a new confusion matrix from a list of reference values and
a corresponding list of test values. |
source code
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int
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__getitem__(self,
(li, lj))
Returns:
The number of times that value li was expected and value
lj was given. |
source code
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pp(self,
show_percents=False,
values_in_chart=True,
truncate=None,
sort_by_count=False)
Returns:
A multi-line string representation of this confusion matrix. |
source code
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_values
A list of all values in reference or test.
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_indices
A dictionary mapping values in self._values to their
indices.
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_confusion
The confusion matrix itself (as a list of lists of counts).
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_max_conf
The greatest count in self._confusion (used for
printing).
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_total
The total number of values in the confusion matrix.
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_correct
The number of correct (on-diagonal) values in the matrix.
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__init__(self,
reference,
test,
sort_by_count=False)
(Constructor)
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Construct a new confusion matrix from a list of reference values and a
corresponding list of test values.
- Parameters:
reference (list) - An ordered list of reference values.test (list) - A list of values to compare against the corresponding reference
values. - Raises:
ValueError - If reference and length do not have the
same length. - Overrides:
object.__init__
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__getitem__(self,
(li, lj))
(Indexing operator)
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- Returns:
int
- The number of times that value
li was expected and
value lj was given.
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- Overrides:
object.__repr__
- (inherited documentation)
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__str__(self)
(Informal representation operator)
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- Overrides:
object.__str__
- (inherited documentation)
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pp(self,
show_percents=False,
values_in_chart=True,
truncate=None,
sort_by_count=False)
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- Parameters:
truncate (int) - If specified, then only show the specified number of values. Any
sorting (e.g., sort_by_count) will be performed before
truncation.sort_by_count - If true, then sort by the count of each label in the reference
data. I.e., labels that occur more frequently in the reference
label will be towards the left edge of the matrix, and labels
that occur less frequently will be towards the right edge. - Returns:
- A multi-line string representation of this confusion matrix.
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