code: def from_binary(cls,pst,filename):
          
          m = Matrix.from_binary(filename)
          return ObservationEnsemble(data=m.x,pst=pst, index=m.row_names)
docs: instantiate an observation obsemble from a jco-type file
  
          Parameters
          ----------
          pst : pyemu.Pst
              a Pst instance
          filename : str
              the binary file name
  
          Returns
          -------
          oe : ObservationEnsemble