class_docstr: Class to hold results from fitting a state space model.
  
  Parameters
  ----------
  model : MLEModel instance
      The fitted model instance
  params : ndarray
      Fitted parameters
  
  Attributes
  ----------
  model : Model instance
      A reference to the model that was fit.
  nobs : float
      The number of observations used to fit the model.
  params : ndarray
      The parameters of the model.
class_docstr_tok: ["Class","to","hold","results","from","fitting","a","state","space","model",".","Parameters","--","--","--","--","--","model",":","MLEModel","instance","The","fitted","model","instance","params",":","ndarray","Fitted","parameters","Attributes","--","--","--","--","--","model",":","Model","instance","A","reference","to","the","model","that","was","fit",".","nobs",":","float","The","number","of","observations","used","to","fit","the","model",".","params",":","ndarray","The","parameters","of","the","model","."]
docstr: Returns a valid numeric start index for predictions/simulations
docstr_tok: ["Returns","a","valid","numeric","start","index","for","predictions\/simulations"]
code: def _get_prediction_start_index(self, anchor):
      """Returns a valid numeric start index for predictions/simulations"""
      if anchor is None or anchor == "start":
          iloc = 0
      elif anchor == "end":
          iloc = self.nobs
      else:
          iloc, _, _ = self.model._get_index_loc(anchor)
          if isinstance(iloc, slice):
              iloc = iloc.start
          iloc += (
              1  # anchor is one before start of prediction/simulation
          )
  
      if iloc < 0:
          iloc = self.nobs + iloc
      if iloc > self.nobs:
          raise ValueError(
              "Cannot anchor simulation outside of the sample."
          )
      return iloc
  
imports: from collections import OrderedDict
  import contextlib
  import warnings
  import numpy
  import pandas
  from scipy.stats import norm
  from statsmodels.base.data import PandasData
  from statsmodels.tools.decorators import cache_readonly
  from statsmodels.tools.eval_measures import aic, aicc, bic, hqic
  from statsmodels.tools.sm_exceptions import PrecisionWarning
  from statsmodels.tools.numdiff import _get_epsilon, approx_fprime, approx_fprime_cs, approx_hess_cs
  from statsmodels.tools.tools import pinv_extended
  import statsmodels.tsa.base.tsa_model
  from statsmodels.tsa.statespace.tools import _safe_cond
label_desc: Use image node_id 16 for calling the StateSpaceMLEResults obj's underlying member method code with example usage: obj._get_prediction_start_index(anchor) and returns: iloc