def front(self, *fields):
        ts = self.irange(0, 0, fields=fields)
        if ts:
            return ts.start(), ts[0]
Calculates the error between the two given values.
dataset/ETHPy150Open lsbardel/python-stdnet/stdnet/apps/columnts/npts.py/ColumnTS.front--crossover with--dataset/ETHPy150Open T-002/pycast/pycast/errors/symmetricmeanabsolutepercentageerror.py/SymmetricMeanAbsolutePercentageError.local_error