[R] Selecting elements

[Jeff Newmiller]

Well, I don't think language is as much of a problem as your failure to compose your messages using plain text format. Your examples are all mushed together since the mailing list removes formatting. See what we see below for example.

On August 20, 2021 12:27:50 PM PDT, Silvano Cesar da Costa <silvano using uel.br> wrote:
>Hi, thanks you for the answer.
>Sorry English is not my native language.
>
>But you got it right.
>> As C is first and fourth biggest value, you follow third option and
>select 3 highest A, 3B 2C and 2D?
>
>I must select the 10 (not 15) highest values, but which follow a certain
>order:
>3A - 3B - 2C - 2D     or
>2A - 5B - 0C - 3D     or
>3A - 3B - 2C - 2D
>
>I'll put the example in Excel for a better understanding (with 20 elements
>only).
>I must select 10 elements (the highest values of variable Var.2), which fit
>one of the 3 options above.
>
>Number Position Var.1 Var.2
>1 27 C 40
>2 30 B 39 Selected:
>3 5 A 38 Number Position Var.1 Var.2
>4 16 D 37 1 27 C 40
>5 23 C 36 2 30 B 39   3A - 3B - 2C - 2D
>6 13 A 35 3 5 A 38
>7 20 D 34 4 16 D 37 3A - 3B - 1C - 3D
>8 12 D 33 5 23 C 36
>9 9 A 32 6 13 A 35 2A - 5B - 0C - 3D
>10 1 A 31 7 20 D 34
>11 21 A 30 10 9 A 32
>12 35 C 29 13 14 B 28
>13 14 B 28 17 6 B 25
>14 8 D 27
>15 7 C 26
>16 6 B 25
>17 40 D 24
>18 26 B 23
>19 29 A 22
>20 31 C 21
>
>
>
>Second option (other data set):
>
>Number Position Var.1 Var.2
>1 36 D 20
>2 11 B 19 Selected:
>3 39 A 18 Number Position Var.1 Var.2
>4 24 D 17 1 36 D 20
>5 34 B 16 2 11 B 19   3A - 3B - 2C - 2D
>6 2 B 15 3 39 A 18
>7 3 A 14 4 24 D 17   3A - 3B - 1C - 3D
>8 32 D 13 5 34 B 16
>9 28 D 12 6 2 B 15 2A - 5B - 0C - 3D
>10 25 A 11 7 3 A 14
>11 19 B 10 8 32 D 13
>12 15 B 9 9 25 A 11
>13 17 A 8 10 18 C 7
>14 18 C 7
>15 38 B 6
>16 10 B 5
>17 22 B 4
>18 4 D 3
>19 33 A 2
>20 37 A 1
>
>
>How to make the selection of these 10 elements that fit one of the 3
>options using R?
>
>Thanks,
>
>Prof. Dr. Silvano Cesar da Costa
>Universidade Estadual de Londrina
>Centro de Ciências Exatas
>Departamento de Estatística
>
>Fone: (43) 3371-4346
>
>
>Em sex., 20 de ago. de 2021 às 03:28, PIKAL Petr <petr.pikal using precheza.cz>
>escreveu:
>
>> 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]]
>> >
>> > ______________________________________________
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>> > guide.html
>> > and provide commented, minimal, self-contained, reproducible code.
>>
>
>	[[alternative HTML version deleted]]
>
>______________________________________________
>R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
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-- 
Sent from my phone. Please excuse my brevity.