select

select(v, k, [by=,] [lt=,] [rev=false])

Variant of select! which copies v before partially sorting it, thereby returning the same thing as select! but leaving v unmodified.

Examples

In the Julia programming language, the function select(v, k, [by=<transform>,] [lt=<comparison>,] [rev=false]) is a variant of select!. It returns a partially sorted copy of v without modifying the original v array. The select function allows you to select the k-th element from v based on optional sorting and filtering criteria.

julia> select([6, 5, 4, 3, 2, 1], 3)
3

julia> select([6, 5, 4, 3, 2, 1], 3, lt=<)
4

julia> select([6, 5, 4, 3, 2, 1], 3, by=x -> x^2)
9

julia> select(["apple", "banana", "orange", "grape"], 2)
"banana"

julia> select(["apple", "banana", "orange", "grape"], 2, by=length)
"grape"

Common examples of its use:

Select the k-th smallest element from an array:
```
julia> select([6, 5, 4, 3, 2, 1], 3)
3
```
This example selects the 3rd smallest element from the given array.
Select the k-th smallest element using a custom comparison:
```
julia> select([6, 5, 4, 3, 2, 1], 3, lt=<)
4
```
The lt=< argument specifies the less-than comparison operator. This example selects the 3rd smallest element using the custom comparison.
Select the k-th element based on a transformation:
```
julia> select([6, 5, 4, 3, 2, 1], 3, by=x -> x^2)
9
```
The by=x -> x^2 argument applies the transformation x^2 before selecting the k-th element. In this case, it selects the 3rd smallest squared element.
Select the k-th element from an array of strings:
```
julia> select(["apple", "banana", "orange", "grape"], 2)
"banana"
```
It selects the 2nd element from an array of strings.
Select the k-th element based on a transformation for strings:
```
julia> select(["apple", "banana", "orange", "grape"], 2, by=length)
"grape"
```
The by=length argument applies the length function before selecting the k-th element based on the length of the strings.

Note: Since select creates a copy of the array v, it can be used to extract elements without modifying the original array.

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select

Examples

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