class_docstr: Inherits time series methods from TSM class.
  
  **** GENERALIZED AUTOREGRESSIVE SCORE (GAS) MODELS ****
  
  Parameters
  ----------
  data : pd.DataFrame or np.array
      Field to specify the univariate time series data that will be used.
  
  ar : int
      Field to specify how many AR lags the model will have.
  
  sc : int
      Field to specify how many score lags terms the model will have.
  
  family : GAS family object
      Which distribution to use, e.g. GASNormal()
  
  integ : int (default : 0)
      Specifies how many time to difference the time series.
  
  target : str (pd.DataFrame) or int (np.array)
      Specifies which column name or array index to use. By default, first
      column/array will be selected as the dependent variable.
docstr: Obtains appropriate model scale and shape latent variables
  
  Parameters
  ----------
  parm : np.array
      Transformed latent variable vector
  
  Returns
  ----------
  None (changes model attributes)
docstr_tok: ["Obtains","appropriate","model","scale","and","shape","latent","variables","Parameters","--","--","--","--","--","parm",":","np.array","Transformed","latent","variable","vector","Returns","--","--","--","--","--","None","(","changes","model","attributes",")"]
code: def _get_scale_and_shape(self, parm):
      """Obtains appropriate model scale and shape latent variables
  
      Parameters
      ----------
      parm : np.array
          Transformed latent variable vector
  
      Returns
      ----------
      None (changes model attributes)
      """
  
      if self.scale is True:
          if self.shape is True:
              model_shape = parm[-1]
              model_scale = parm[-2]
          else:
              model_shape = 0
              model_scale = parm[-1]
      else:
          model_scale = 0
          model_shape = 0
  
      if self.skewness is True:
          model_skewness = parm[-3]
      else:
          model_skewness = 0
  
      return model_scale, model_shape, model_skewness
  
imports: import sys
  import numpy
  import pandas
  import scipy.stats
  import scipy.special
  from ..None import families
  from ..None import tsm
  from ..None import data_check
  from .gas_core_recursions import gas_recursion
label_desc: Use image node_id 4 for calling the GAS obj's underlying member method code with example usage: obj._get_scale_and_shape(parm) and returns: model_scale,  model_shape,  model_skewness