Exemplo n.º 1
0
 def fit(self):
     '''
     Fit a Holt-winters method of type={linear, additive, multiplicative} on data
     
     Return
     ----------
     params: Array-like Parameters of the model [alpha, beta, gamma, m] depending on the type
     RMSE: Root Mean Squared Error of the model when fit to the data
     '''
     rmse = 0.0
     y = self.data
     
     if self.type == 'linear':
         initial_values = array([0.3, 0.1])
         boundaries = [(0, 1), (0, 1)]
  
         parameters = fmin_l_bfgs_b(self.RMSE, x0 = initial_values, args = (y, self.type), bounds = boundaries, approx_grad = True)
         self.alpha, self.beta = parameters[0]
         rmse = parameters[1]
         return [self.alpha, self.beta], rmse
         
     elif self.type == 'additive':
         self.m = tsutils.findDominentSeason(y)
      
         initial_values = array([0.3, 0.1, 0.1])
         boundaries = [(0, 1), (0, 1), (0, 1)]
  
         parameters = fmin_l_bfgs_b(self.RMSE, x0 = initial_values, args = (y, self.type, self.m), bounds = boundaries, approx_grad = True)
         self.alpha, self.beta, self.gamma = parameters[0]
         rmse = parameters[1]
         
         return [self.alpha, self.beta, self.gamma, self.m], rmse
         
     elif self.type == 'multiplicative':
         self.m = tsutils.findDominentSeason(y)
         
         initial_values = array([0.0, 1.0, 0.0])
         boundaries = [(0, 1), (0, 1), (0, 1)]
  
         parameters = fmin_l_bfgs_b(self.RMSE, x0 = initial_values, args = (y, self.type, self.m), bounds = boundaries, approx_grad = True)
         self.alpha, self.beta, self.gamma = parameters[0]
         rmse = parameters[1]
         
         return [self.alpha, self.beta, self.gamma, self.m], rmse 
Exemplo n.º 2
0
 def fit(self):
     '''
     Fit a Holt-winters method of type={linear, additive, multiplicative} on data
     
     Return
     ----------
     params: Array-like Parameters of the model [alpha, beta, gamma, m] depending on the type
     RMSE: Root Mean Squared Error of the model when fit to the data
     '''
     rmse = 0.0
     y = self.data[:]
     
     if self.type == 'linear':
         initial_values = array([0.3, 0.1])
         boundaries = [(0, 1), (0, 1)]
  
         parameters = fmin_l_bfgs_b(self.RMSE, x0 = initial_values, args = (y, self.type), bounds = boundaries, approx_grad = True)
         self.alpha, self.beta = parameters[0]
         rmse = parameters[1]
         return [self.alpha, self.beta], rmse
         
     elif self.type == 'additive':
         self.m = tsutils.findDominentSeason(y)
      
         initial_values = array([0.3, 0.1, 0.1])
         boundaries = [(0, 1), (0, 1), (0, 1)]
  
         parameters = fmin_l_bfgs_b(self.RMSE, x0 = initial_values, args = (y, self.type, self.m), bounds = boundaries, approx_grad = True)
         self.alpha, self.beta, self.gamma = parameters[0]
         rmse = parameters[1]
         
         return [self.alpha, self.beta, self.gamma, self.m], rmse
         
     elif self.type == 'multiplicative':
         self.m = tsutils.findDominentSeason(y)
         
         initial_values = array([0.0, 1.0, 0.0])
         boundaries = [(0, 1), (0, 1), (0, 1)]
  
         parameters = fmin_l_bfgs_b(self.RMSE, x0 = initial_values, args = (y, self.type, self.m), bounds = boundaries, approx_grad = True)
         self.alpha, self.beta, self.gamma = parameters[0]
         rmse = parameters[1]
         
         return [self.alpha, self.beta, self.gamma, self.m], rmse 
Exemplo n.º 3
0
 def update(self,data):
     '''
     Updates the Holt-winters model by re-estimating the paramters {alpha, beta, gamma, m} depending
     on the model type
     '''
     self.data = data[:].tolist()
     y = self.data[:]
     if self.type == 'linear':
         initial_values = array([self.alpha, self.beta])
         boundaries = [(0, 1), (0, 1)]
  
         parameters = fmin_l_bfgs_b(self.RMSE, x0 = initial_values, args = (y, self.type), bounds = boundaries, approx_grad = True)
         self.alpha, self.beta = parameters[0]
         rmse = parameters[1]
         return [self.alpha, self.beta], rmse
         
     elif self.type == 'additive':
         self.m = tsutils.findDominentSeason(y)
      
         initial_values = array([self.alpha, self.beta, self.gamma])
         boundaries = [(0, 1), (0, 1), (0, 1)]
  
         parameters = fmin_l_bfgs_b(self.RMSE, x0 = initial_values, args = (y, self.type, self.m), bounds = boundaries, approx_grad = True)
         self.alpha, self.beta, self.gamma = parameters[0]
         rmse = parameters[1]
         
         return [self.alpha, self.beta, self.gamma, self.m], rmse
         
     elif self.type == 'multiplicative':
         self.m = tsutils.findDominentSeason(y)
         
         initial_values = array([self.alpha, self.beta, self.gamma])
         boundaries = [(0, 1), (0, 1), (0, 1)]
  
         parameters = fmin_l_bfgs_b(self.RMSE, x0 = initial_values, args = (y, self.type, self.m), bounds = boundaries, approx_grad = True)
         self.alpha, self.beta, self.gamma = parameters[0]
         rmse = parameters[1]
Exemplo n.º 4
0
 def update(self,data):
     '''
     Updates the Holt-winters model by re-estimating the paramters {alpha, beta, gamma, m} depending
     on the model type
     '''
     self.data = data[:]
     y = self.data[:]
     if self.type == 'linear':
         initial_values = array([self.alpha, self.beta])
         boundaries = [(0, 1), (0, 1)]
  
         parameters = fmin_l_bfgs_b(self.RMSE, x0 = initial_values, args = (y, self.type), bounds = boundaries, approx_grad = True)
         self.alpha, self.beta = parameters[0]
         rmse = parameters[1]
         return [self.alpha, self.beta], rmse
         
     elif self.type == 'additive':
         self.m = tsutils.findDominentSeason(y)
      
         initial_values = array([self.alpha, self.beta, self.gamma])
         boundaries = [(0, 1), (0, 1), (0, 1)]
  
         parameters = fmin_l_bfgs_b(self.RMSE, x0 = initial_values, args = (y, self.type, self.m), bounds = boundaries, approx_grad = True)
         self.alpha, self.beta, self.gamma = parameters[0]
         rmse = parameters[1]
         
         return [self.alpha, self.beta, self.gamma, self.m], rmse
         
     elif self.type == 'multiplicative':
         self.m = tsutils.findDominentSeason(y)
         
         initial_values = array([self.alpha, self.beta, self.gamma])
         boundaries = [(0, 1), (0, 1), (0, 1)]
  
         parameters = fmin_l_bfgs_b(self.RMSE, x0 = initial_values, args = (y, self.type, self.m), bounds = boundaries, approx_grad = True)
         self.alpha, self.beta, self.gamma = parameters[0]
         rmse = parameters[1]
Exemplo n.º 5
0
    def fit(self):
        '''
        Fits a model: First smoothes the data using a Median filter. Then determines if a pattern exists
        by calculating the dominant period and splitting the time series into pattern windows.
        For each adjacent pair of the pattern widows, the Pearson-Correlation is calculated and compared 
        to the threshold together with the two pattern means. If the pattern exists for more than the match_ratio
        a Signature pattern is calculated using the original data and pattern windows that match.
        
        **Note: If no pattern is found, a 1st order Markov model is trained on the data instead
        '''
        self.markov.fit()
        # Smooth data and dominant period
        smooth = signal.medfilt(self.data, self.window)
        Z = tsutils.findDominentSeason(self.data)
        #         Z=288
        # Determine the number of pattern windows and split smoothed data
        Q = np.int(np.ceil(1.0 * self.N / Z))
        if Q > 2:
            idx = range(Z, Q * Z, Z)
            P = np.array(np.split(smooth, idx))
            self.P = P
            self.warp = P[-1].shape[0] != P[-2].shape[0]
            # Check pattern exist
            PC = []
            MR = []
            for i in range(Q - 1 - self.warp):
                PC.append(stats.pearsonr(P[i], P[i + 1])[0])
                MR.append(np.mean(P[i]) / np.mean(P[i + 1]))

            # Test if pattern exist
            if np.all(PC > self.corr_thres):
                self.contain_pat = True
                Pr = np.array(np.split(self.data, idx))
                if self.warp:
                    self.sig = np.average(Pr[:-1], axis=0)
                else:
                    self.sig = np.average(Pr, axis=0)
Exemplo n.º 6
0
    def fit(self):
        '''
        Fits a model: First smoothes the data using a Median filter. Then determines if a pattern exists
        by calculating the dominant period and splitting the time series into pattern windows.
        For each adjacent pair of the pattern widows, the Pearson-Correlation is calculated and compared 
        to the threshold together with the two pattern means. If the pattern exists for more than the match_ratio
        a Signature pattern is calculated using the original data and pattern windows that match.
        
        **Note: If no pattern is found, a 1st order Markov model is trained on the data instead
        '''
        self.markov.fit()
        # Smooth data and dominant period
        smooth = signal.medfilt(self.data, self.window)
        Z = tsutils.findDominentSeason(self.data)
#         Z=288
        # Determine the number of pattern windows and split smoothed data
        Q = np.int(np.ceil(1.0*self.N/Z))
        if Q > 2:
            idx = range(Z,Q*Z,Z)
            P = np.array(np.split(smooth, idx))
            self.P = P
            self.warp = P[-1].shape[0] != P[-2].shape[0]
            # Check pattern exist
            PC = []
            MR = []
            for i in range(Q-1-self.warp):
                PC.append(stats.pearsonr(P[i], P[i+1])[0])
                MR.append(np.mean(P[i])/np.mean(P[i+1]))
                
            # Test if pattern exist
            if np.all(PC>self.corr_thres):
                self.contain_pat = True
                Pr = np.array(np.split(self.data, idx))
                if self.warp:
                    self.sig = np.average(Pr[:-1],axis=0)
                else:
                    self.sig = np.average(Pr,axis=0)