# Boolean Indexing in dataframes
**URL:** https://discourse.julialang.org/t/boolean-indexing-in-dataframes/99692
**Category:** Data
**Tags:** question, dataframes
**Created:** [May 31, 2023, 8:53pm UTC](https://discourse.julialang.org/t/boolean-indexing-in-dataframes/99692 "2023-05-31T20:53:03Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@Ordens\_Ritter](https://discourse.julialang.org/u/Ordens_Ritter)
#### Post date: [May 31, 2023, 8:53pm UTC](https://discourse.julialang.org/t/boolean-indexing-in-dataframes/99692/1 "2023-05-31T20:53:03Z")
> [@Indexing a DataFrame with a boolean DataFrame](https://discourse.julialang.org/t/indexing-a-dataframe-with-a-boolean-dataframe/83108/1):
>
> et some values across a whole datafame using a boolean mask, similarly to this example with plain arrays:
@bkamins How about sampling the dataframe by boolean values. I mean take every column for the row, the the boolean is true?
Like this example:
```julia
julia> df = DataFrame(rand(3,3), :auto)
3×3 DataFrame
Row │ x1 x2 x3
│ Float64 Float64 Float64
─────┼───────────────────────────────
1 │ 0.045519 0.468771 0.387336
2 │ 0.0133922 0.383619 0.418809
3 │ 0.870746 0.898979 0.628106
```
For example: I want to get every dataframe, at every row where x1 is larger 0.02
---
### Author:  [@awasserman](https://discourse.julialang.org/u/awasserman)
#### Post date: [May 31, 2023, 8:58pm UTC](https://discourse.julialang.org/t/boolean-indexing-in-dataframes/99692/2 "2023-05-31T20:58:47Z")
I’m not sure I follow the original question, but for the example you can do
```julia
df[df.x1 .> 0.02, :]
```
to select the subset of rows satisfying the desired criterion.
Alternatively, you can use the subset function:
```julia
subset(df, :x1 => ByRow(>(0.02)))
```
---
### Author:  [@pdeffebach](https://discourse.julialang.org/u/pdeffebach)
#### Post date: [May 31, 2023, 9:19pm UTC](https://discourse.julialang.org/t/boolean-indexing-in-dataframes/99692/3 "2023-05-31T21:19:01Z")
In DataFramesMeta.jl, this is simply
```julia
@rsubset df :x1 > .02
```
---
### Author:  [@math4mad](https://discourse.julialang.org/u/math4mad)
#### Post date: [December 14, 2023, 2:17pm UTC](https://discourse.julialang.org/t/boolean-indexing-in-dataframes/99692/4 "2023-12-14T14:17:45Z")
I think maybe you want this:
```julia-auto
using Tidier,DataFrames
df = DataFrame(a = [1, 2, missing, 4, 5])
```
## @filter
```julia-auto
@chain df begin
@filter(a >=2))
end
```
## Conditionals
```julia-auto
@chain df begin
@mutate(a = if_else(a >= 2, true, false))
end
```