class_docstr: Short Panel with general intertemporal within correlation
  
  assumes data is stacked by individuals, panel is balanced and
  within correlation structure is identical across individuals.
  
  It looks like this can just inherit GLS and overwrite whiten
class_docstr_tok: ["Short","Panel","with","general","intertemporal","within","correlation","assumes","data","is","stacked","by","individuals",",","panel","is","balanced","and","within","correlation","structure","is","identical","across","individuals",".","It","looks","like","this","can","just","inherit","GLS","and","overwrite","whiten"]
code: def __init__(self, endog, exog, group):
      self.endog = endog
      self.exog = exog
      self.group = GroupSorted(group)
      self.n_groups = self.group.n_groups
  
imports: import numpy
  from statsmodels.regression.linear_model import OLS, GLS
  from statsmodels.tools.grouputils import GroupSorted
label_desc: Use image node_id 1 to create a new ShortPanelGLS2 object  with example: obj = ShortPanelGLS2(endog, exog, group)