code: def Y(self, value):
          
          self._N = value.shape[0]
          self._P = value.shape[1]
          self._Y = value
          # missing data
          self._Iok = ~sp.isnan(value)
          self._veIok = vec(self._Iok)[:, 0]
          self._miss = (~self._Iok).any()
          # notify and clear_cached
          self.clear_cache('pheno')
          self._notify()
          self._notify('pheno')
docs: set phenotype