'Get the group parameter value.'

def par(self, parname):

    if _is_int(parname):
        result = self.array[self.row][parname]
    else:
        indx = self._unique[parname.upper()]
        if (len(indx) == 1):
            result = self.array[self.row][indx[0]]
        else:
            result = self.array[self.row][indx[0]].astype('f8')
            for i in indx[1:]:
                result += self.array[self.row][i]
    return result
