Aggregate a tabarray on columns for given functions.

        Method wraps::

                tabular.spreadsheet.aggregate(self, On, AggFuncDict, AggFunc, returnsort)

def aggregate(self, On=None, AggFuncDict=None, AggFunc=None, AggList =
                  None, returnsort=False,KeepOthers=True, keyfuncdict=None):
        """
        Aggregate a tabarray on columns for given functions.

        Method wraps::

                tabular.spreadsheet.aggregate(self, On, AggFuncDict, AggFunc, returnsort)

        """
        if returnsort:
            [data, s] = spreadsheet.aggregate(X=self, 
                     On=On, 
                     AggFuncDict=AggFuncDict, 
                     AggFunc=AggFunc, 
                     AggList=AggList, 
                     returnsort=returnsort, 
                     keyfuncdict=keyfuncdict)
        else:
            data = spreadsheet.aggregate(X=self, On=On, AggFuncDict=AggFuncDict, 
                     AggFunc=AggFunc, AggList = AggList, returnsort=returnsort, 
                     KeepOthers=KeepOthers,
                     keyfuncdict=keyfuncdict)
        data = data.view(tabarray)
        data.coloring = self.coloring
        if returnsort:
            return [data, s]
        else:
            return data