corny85
#1
Hello,

I’m a beginner with Julia.

I’ve got a dataframe called data that i converted in an array of floats.

```
data_temp = deepcopy(data)
array=Matrix(data_temp[:,2:size(data_temp,2)])
df=Array{Float64}(array)
```

Now, i want to extract from the array df (10 rows and 5 columns)

- a vector{Float64} including the smallest values for the 3 first columns and the highest values for the 2 last columns
- a vector{Float64} including the highest values for the 3 first columns and the smallest values for the 2 last columns

I don’t know how to do it.

Thanks in advance for your help

nilshg
#2
You don’t need a Matrix at all:

```
vec_1 = [minimum.(eachcol(df[!, 1:3]); maximum.(eachcol(df[!, 4:5]))]
```

corny85
#3
I’ve tried:

```
bo=[minimum(df[:,1:3],dims=1);maximum(df[:,4:5],dims=1)]
```

But it doesn’t work.

Why ?

```
minimum(df[:,1:3],dims=1)
```

gives a `1x3`

matrix, which is not a vector. Maybe you want to `collect`

that output so you can `vcat`

them.

The error is pretty self-explanatory imo. Make sure you read the error messages and debug piece by piece.

corny85
#5
ok but how can i concatenate the 1x3 matrix and the 1x2 matrix ?

```
bo=vcat(minimum(df[:,1:3],dims=1),maximum(df[:,4:5],dims=1))
```

doesn’t work

The `vcat`

here is exactly the same as `;`

above.

You can use `hcat`

or, as I wrote above, use `collect`

Please read the responses carefully.

corny85
#7
You are right !

Sorry…and thanks a lot !