示例#1
0
    def __init__(self,
                 sensitivity_analyzer,
                 split_by_labels,
                 select_common_features=True,
                 probability_label=None,
                 probability_combiner=None,
                 selector=FractionTailSelector(0.05),
                 **kwargs):
        '''
        Parameters
        ----------
        sensitivity_analyzer: FeaturewiseMeasure
            Sensitivity analyzer to come up with sensitivity.
        split_by_labels: str or list of str
            Sample labels on which input datasets are split before
            data is selected.
        select_common_features: bool
            True means that the same features are selected after the split.
        probablity_label: None or str
            If None, then the output dataset ds from the
            sensitivity_analyzer is taken to select the samples.
            If not None it takes ds.sa['probablity_label'].
            For example if sensitivity_analyzer=OneWayAnova then
            probablity_label='fprob' is a sensible value.
        probability_combiner: function
            If select_common_features is True, then this function is
            applied to the feature scores across splits. If None,
            it uses lambda x:np.sum(-np.log(x)) which is sensible if
            the scores are probability values
        selector: Selector
            function that returns the indices to keep.
        '''

        SliceMapper.__init__(self, None, **kwargs)

        if probability_combiner is None:

            def f(x):
                y = -np.log(x.ravel())

                # address potential NaNs
                # set to max value in y
                m = np.isnan(y)
                if np.all(m):
                    return 0  # p=1

                y[m] = np.max(y[np.logical_not(m)])
                return np.sum(y)

            probability_combiner = f  # avoid lambda as h5py doesn't like it

        self._sensitivity_analyzer = sensitivity_analyzer
        self._split_by_labels = split_by_labels
        self._select_common_features = select_common_features
        self._probability_label = probability_label
        self._probability_combiner = probability_combiner
        self._selector = selector
示例#2
0
文件: base.py 项目: Arthurkorn/PyMVPA
    def __init__(self,
                 sensitivity_analyzer,
                 split_by_labels,
                 select_common_features=True,
                 probability_label=None,
                 probability_combiner=None,
                 selector=FractionTailSelector(0.05),
                 **kwargs):
        '''
        Parameters
        ----------
        sensitivity_analyzer: FeaturewiseMeasure
            Sensitivity analyzer to come up with sensitivity.
        split_by_labels: str or list of str
            Sample labels on which input datasets are split before
            data is selected.
        select_common_features: bool
            True means that the same features are selected after the split.
        probablity_label: None or str
            If None, then the output dataset ds from the
            sensitivity_analyzer is taken to select the samples.
            If not None it takes ds.sa['probablity_label'].
            For example if sensitivity_analyzer=OneWayAnova then
            probablity_label='fprob' is a sensible value.
        probability_combiner: function
            If select_common_features is True, then this function is
            applied to the feature scores across splits. If None,
            it uses lambda x:np.sum(-np.log(x)) which is sensible if
            the scores are probability values
        selector: Selector
            function that returns the indices to keep.
        '''

        SliceMapper.__init__(self, None, **kwargs)

        if probability_combiner is None:
            def f(x):
                y = -np.log(x.ravel())

                # address potential NaNs
                # set to max value in y
                m = np.isnan(y)
                if np.all(m):
                    return 0 # p=1

                y[m] = np.max(y[np.logical_not(m)])
                return np.sum(y)
            probability_combiner = f # avoid lambda as h5py doesn't like it

        self._sensitivity_analyzer = sensitivity_analyzer
        self._split_by_labels = split_by_labels
        self._select_common_features = select_common_features
        self._probability_label = probability_label
        self._probability_combiner = probability_combiner
        self._selector = selector
示例#3
0
 def __init__(self, filler=0, **kwargs):
     """
     Parameters
     ----------
     filler : optional
       Value to fill empty entries upon reverse operation
     """
     # init slicearg with None
     SliceMapper.__init__(self, None, **kwargs)
     self._dshape = None
     self._oshape = None
     self.filler = filler