# Question about @rtransform?
**URL:** https://discourse.julialang.org/t/question-about-rtransform/83815
**Category:** General Usage
**Created:** [July 6, 2022, 2:57am UTC](https://discourse.julialang.org/t/question-about-rtransform/83815 "2022-07-06T02:57:59Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Raymond](https://discourse.julialang.org/u/Raymond)
#### Post date: [July 6, 2022, 2:57am UTC](https://discourse.julialang.org/t/question-about-rtransform/83815/1 "2022-07-06T02:57:59Z")
Why doesn’t this code work?
```julia
julia> df
4×3 DataFrame
Row │ y x1 x2
│ Int64 Int64 Int64
─────┼─────────────────────
1 │ 2 -97 -999
2 │ 6 2 3
3 │ 3 5 -999
4 │ 5 -97 0
julia> @rtransform df $([:x1, :x2] .=> (x -> x ∈ [-97, -999] ? missing : x) .=> [:x1, :x2])
4×3 DataFrame
Row │ y x1 x2
│ Int64 Int64 Int64
─────┼─────────────────────
1 │ 2 -97 -999
2 │ 6 2 3
3 │ 3 5 -999
4 │ 5 -97 0
```
what I want is
```julia
Row │ y x1 x2
│ Int64 Int64? Int64?
─────┼─────────────────────────
1 │ 2 missing missing
2 │ 6 2 3
3 │ 3 5 missing
4 │ 5 missing 0
```
---
### Author:  [@Raymond](https://discourse.julialang.org/u/Raymond)
#### Post date: [July 6, 2022, 2:59am UTC](https://discourse.julialang.org/t/question-about-rtransform/83815/2 "2022-07-06T02:59:26Z")
`@transform` works, why does not `@rtransform` work?
```julia
@transform df $([:x1, :x2] .=> ByRow(x -> x ∈ [-97, -999] ? missing : x) .=> [:x1, :x2])
4×3 DataFrame
Row │ y x1 x2
│ Int64 Int64? Int64?
─────┼─────────────────────────
1 │ 2 missing missing
2 │ 6 2 3
3 │ 3 5 missing
4 │ 5 missing 0
```