func (a *stddevAggregate) Result() (Datum, error) {
variance, err := a.varianceAggregate.Result()
if err != nil || variance == DNull {
return variance, err
}
switch t := variance.(type) {
case *DFloat:
return NewDFloat(DFloat(math.Sqrt(float64(*t)))), nil
case *DDecimal:
decimal.Sqrt(&t.Dec, &t.Dec, decimal.Precision)
return t, nil
}
return nil, util.Errorf("unexpected variance result type: %s", variance.Type())
}
},
},
"sqrt": {
floatBuiltin1(func(x float64) (Datum, error) {
if x < 0 {
return nil, errSqrtOfNegNumber
}
return DFloat(math.Sqrt(x)), nil
}),
decimalBuiltin1(func(x *inf.Dec) (Datum, error) {
if x.Sign() < 0 {
return nil, errSqrtOfNegNumber
}
dd := &DDecimal{}
decimal.Sqrt(&dd.Dec, x, decimal.Precision)
return dd, nil
}),
},
"tan": {
floatBuiltin1(func(x float64) (Datum, error) {
return DFloat(math.Tan(x)), nil
}),
},
"trunc": {
floatBuiltin1(func(x float64) (Datum, error) {
return DFloat(math.Trunc(x)), nil
}),
decimalBuiltin1(func(x *inf.Dec) (Datum, error) {