[R] Selecting elements

[PIKAL Petr]

Hallo

I am confused, maybe others know what do you want but could you be more specific?

Let say you have such data
set.seed(123)
Var.1 = rep(LETTERS[1:4], 10)
Var.2 = sample(1:40, replace=FALSE)
data = data.frame(Var.1, Var.2)

What should be the desired outcome?

You can sort
data <- data[order(data$Var.2, decreasing=TRUE), ]
and split the data
> split(data$Var.2, data$Var.1)
$A
 [1] 38 35 32 31 30 22 11  8  2  1

$B
 [1] 39 28 25 23 16 15  7  6  5  4

$C
 [1] 40 36 29 26 21 19 18 14 10  9

$D
 [1] 37 34 33 27 24 20 17 13 12  3

T inspect highest values. But here I am lost. As C is first and fourth biggest value, you follow third option and select 3 highest A, 3B 2C and 2D?

Or I do not understand at all what you really want to achieve.

Cheers
Petr

> -----Original Message-----
> From: R-help <r-help-bounces using r-project.org> On Behalf Of Silvano Cesar da
> Costa
> Sent: Thursday, August 19, 2021 10:40 PM
> To: r-help using r-project.org
> Subject: [R] Selecting elements
> 
> Hi,
> 
> I need to select 15 elements, always considering the highest values
> (descending order) but obeying the following configuration:
> 
> 3A - 4B - 0C - 3D or
> 2A - 5B - 0C - 3D or
> 3A - 3B - 2C - 2D
> 
> If I have, for example, 5 A elements as the highest values, I can only choose
> (first and third choice) or 2 (second choice) elements.
> 
> how to make this selection?
> 
> 
> library(dplyr)
> 
> Var.1 = rep(LETTERS[1:4], 10)
> Var.2 = sample(1:40, replace=FALSE)
> 
> data = data.frame(Var.1, Var.2)
> (data = data[order(data$Var.2, decreasing=TRUE), ])
> 
> Elements = data %>%
>   arrange(desc(Var.2))
> 
> Thanks,
> 
> Prof. Dr. Silvano Cesar da Costa
> Universidade Estadual de Londrina
> Centro de Ciências Exatas
> Departamento de Estatística
> 
> Fone: (43) 3371-4346
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-
> guide.html
> and provide commented, minimal, self-contained, reproducible code.