コード例 #1
0
    def fit(self, X, y=None, sample_weight=None):
        """Fit the model with X.

        Parameters
        ----------
        X : Triangle-like
            Set of LDFs to which the tail will be applied.
        y : Ignored
        sample_weight : Ignored

        Returns
        -------
        self : object
            Returns the instance itself.
        """
        super().fit(X, y, sample_weight)
        decay_range = self.ldf_.shape[-1]-X.shape[-1]+1
        ldfs = 1+self._get_initial_ldf()*(self.decay**np.arange(1000))
        ldfs = ldfs[:decay_range]
        ldfs[-1] = self.tail/np.prod(ldfs[:-1])
        ldfs = X._expand_dims(ldfs[np.newaxis])
        self.ldf_.values[..., -decay_range:] = \
            self.ldf_.values[..., -decay_range:]*ldfs
        self.cdf_ = DevelopmentBase._get_cdf(self)
        return self
コード例 #2
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ファイル: clark.py プロジェクト: Synergist/chainladder-python
    def fit(self, X, y=None, sample_weight=None):
        """Fit the model with X.

        Parameters
        ----------
        X : Triangle-like
            Set of LDFs to which the tail will be applied.
        y : Ignored
        sample_weight : Triangle-like
            Exposure vector used to invoke the Cape Cod method.

        Returns
        -------
        self : object
            Returns the instance itself.
        """
        super().fit(X, y, sample_weight)
        model = ClarkLDF(growth=self.growth).fit(X,
                                                 sample_weight=sample_weight)
        xp = cp.get_array_module(X.values)
        age_offset = {'Y': 6., 'Q': 1.5, 'M': 0.5}[X.development_grain]
        tail = 1 / model.G_(
            xp.array([
                item * self._ave_period[1] + X.ddims[-1] - age_offset
                for item in range(self._ave_period[0] + 1)
            ]))
        tail = xp.concatenate((tail.values[..., :-1] / tail.values[..., -1],
                               tail.values[..., -1:]), -1)
        self.ldf_.values = xp.concatenate(
            (X.ldf_.values, xp.repeat(tail, X.shape[2], 2)), -1)
        self.cdf_ = DevelopmentBase._get_cdf(self)
        return self
コード例 #3
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 def fit(self, X, y=None, sample_weight=None):
     obj = copy.copy(X)
     if 'ldf_'not in obj:
         obj = Development().fit_transform(obj)
     self._ave_period = {'Y': (1, 12),
                         'Q': (4, 3),
                         'M': (12, 1)}[obj.development_grain]
     ddims = np.concatenate(
         (obj.ddims, [(item+1)*self._ave_period[1] + obj.ddims[-1]
                      for item in range(self._ave_period[0])], [9999]), 0)
     self.ldf_ = copy.copy(obj.ldf_)
     tail = np.ones(self.ldf_.shape)[..., -1:]
     tail = np.repeat(tail, self._ave_period[0]+1, -1)
     self.ldf_.values = np.concatenate((self.ldf_.values, tail), -1)
     self.ldf_.ddims = np.array(['{}-{}'.format(ddims[i], ddims[i+1])
                                 for i in range(len(ddims)-1)])
     self.ldf_.valuation = self.ldf_._valuation_triangle()
     self.sigma_ = copy.copy(getattr(obj, 'sigma_', obj.cdf_*0))
     self.std_err_ = copy.copy(getattr(obj, 'std_err_', obj.cdf_*0))
     zeros = tail[..., -1:]*0
     self.sigma_.values = np.concatenate(
         (self.sigma_.values, zeros), -1)
     self.std_err_.values = np.concatenate(
         (self.std_err_.values, zeros), -1)
     self.sigma_.ddims = self.std_err_.ddims = \
         np.append(obj.ldf_.ddims, ['{}-9999'.format(int(obj.ddims[-1]))])
     val_array = self.sigma_._valuation_triangle(self.sigma_.ddims)
     self.sigma_.valuation = self.std_err_.valuation = val_array
     self.cdf_ = DevelopmentBase._get_cdf(self)
     self.cdf_.set_slicers()
     self.ldf_.set_slicers()
     self.sigma_.set_slicers()
     self.std_err_.set_slicers()
     return self
コード例 #4
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ファイル: curve.py プロジェクト: zluety/chainladder-python
    def fit(self, X, y=None, sample_weight=None):
        """Fit the model with X.

        Parameters
        ----------
        X : Triangle-like
            Set of LDFs to which the tail will be applied.
        y : Ignored
        sample_weight : Ignored

        Returns
        -------
        self : object
            Returns the instance itself.
        """
        super().fit(X, y, sample_weight)
        xp = cp.get_array_module(self.ldf_.values)
        _y = self.ldf_.values[..., :X.shape[-1] - 1].copy()
        _w = xp.zeros(_y.shape)
        if type(self.fit_period) is not slice:
            raise TypeError('fit_period must be slice.')
        else:
            _w[..., self.fit_period] = 1.0
        if self.errors == 'ignore':
            _w[_y <= 1.0] = 0
            _y[_y <= 1.0] = 1.01
        elif self.errors == 'raise' and xp.any(y < 1.0):
            raise ZeroDivisionError('Tail fit requires all LDFs to be' +
                                    ' greater than 1.0')
        _y = xp.log(_y - 1)
        n_obs = X.shape[-1] - 1
        k, v = X.shape[:2]
        _x = self._get_x(_w, _y)
        # Get LDFs
        coefs = WeightedRegression(axis=3).fit(_x, _y, _w)
        slope, intercept = coefs.slope_, coefs.intercept_
        extrapolate = xp.cumsum(
            xp.ones(tuple(list(_y.shape)[:-1] +
                          [self.extrap_periods + n_obs])), -1)
        tail = self._predict_tail(slope, intercept, extrapolate)
        if self.attachment_age:
            attach_idx = xp.min(xp.where(X.ddims >= self.attachment_age))
        else:
            attach_idx = len(X.ddims) - 1
        self.ldf_.values = xp.concatenate(
            (self.ldf_.values[..., :attach_idx], tail[..., attach_idx:]), -1)
        obj = Development().fit_transform(X) if 'ldf_' not in X else X
        sigma, std_err = self._get_tail_stats(obj)
        self.sigma_.values[..., -1] = sigma[..., -1]
        self.std_err_.values[..., -1] = std_err[..., -1]
        self.slope_ = slope
        self.intercept_ = intercept
        self.cdf_ = DevelopmentBase._get_cdf(self)
        return self
コード例 #5
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ファイル: curve.py プロジェクト: abirr97/chainladder-python
    def fit(self, X, y=None, sample_weight=None):
        """Fit the model with X.

        Parameters
        ----------
        X : Triangle-like
            Set of LDFs to which the tail will be applied.
        y : Ignored
        sample_weight : Ignored

        Returns
        -------
        self : object
            Returns the instance itself.
        """
        super().fit(X, y, sample_weight)
        _y = self.ldf_.values[..., :-1].copy()
        _w = np.zeros(_y.shape)
        if type(self.fit_period) is not slice:
            raise TypeError('fit_period must be slice.')
        else:
            _w[..., self.fit_period] = 1.0
        if self.errors == 'ignore':
            _w[_y <= 1.0] = 0
            _y[_y <= 1.0] = 1.01
        elif self.errors == 'raise' and np.any(y < 1.0):
            raise ZeroDivisionError('Tail fit requires all LDFs to be \
                                     greater than 1.0')
        _y = np.log(_y - 1)
        n_obs = X.shape[-1] - 1
        k, v = X.shape[:2]
        _x = self._get_x(_w, _y)
        # Get LDFs
        coefs = WeightedRegression(axis=3).fit(_x, _y, _w)
        slope, intercept = coefs.slope_, coefs.intercept_
        extrapolate = np.cumsum(
            np.ones(tuple(list(_y.shape)[:-1] + [self.extrap_periods])),
            -1) + n_obs
        tail = self._predict_tail(slope, intercept, extrapolate)
        self.ldf_.values = self.ldf_.values[..., :-tail.shape[-1]]
        self.ldf_.values = np.concatenate((self.ldf_.values, tail), -1)
        if X.__dict__.get('ldf_', None) is None:
            obj = Development().fit_transform(X)
        else:
            obj = X
        sigma, std_err = self._get_tail_stats(obj)
        self.sigma_.values[..., -1] = sigma[..., -1]
        self.std_err_.values[..., -1] = std_err[..., -1]
        self.slope_ = slope
        self.intercept_ = intercept
        self.cdf_ = DevelopmentBase._get_cdf(self)
        return self
コード例 #6
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ファイル: base.py プロジェクト: Synergist/chainladder-python
 def _apply_decay(self, X, tail):
     ''' Created Tail vector with decay over time '''
     xp = cp.get_array_module(X.values)
     decay_range = self.ldf_.shape[-1] - X.shape[-1] + 1
     if xp.max(tail) == 1.0:
         ldfs = 1 + 0 * (self.decay**xp.arange(1000))
     else:
         ldfs = 1 + self._get_initial_ldf(xp, tail) * (self.decay**
                                                       xp.arange(1000))
     ldfs = ldfs[..., :decay_range]
     ldfs[..., -1:] = tail / xp.prod(ldfs[..., :-1], axis=-1, keepdims=True)
     self.ldf_.values[..., -decay_range:] = \
         self.ldf_.values[..., -decay_range:]*ldfs
     self.cdf_ = DevelopmentBase._get_cdf(self)
     return self
コード例 #7
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    def fit(self, X, y=None, sample_weight=None):
        """Fit the model with X.

        Parameters
        ----------
        X : Triangle-like
            Set of LDFs to which the tail will be applied.
        y : Ignored
        sample_weight : Ignored

        Returns
        -------
        self : object
            Returns the instance itself.
        """
        super().fit(X, y, sample_weight)
        self.ldf_.values[..., -1] = self.ldf_.values[..., -1] * self.tail
        self.cdf_ = DevelopmentBase._get_cdf(self)
        return self