[R] Select

[Göran Broström]

On 2019-02-11 23:35, Val wrote:
> Hi all,
> 
> I have a data frame  with tow variables  group and its size.
> mydat<- read.table( text='group  count
> G1 25
> G2 15
> G3 12
> G4 31
> G5 10' , header = TRUE, as.is = TRUE )
> 

How about

x <- sample(1:5)

total <- mydat$count[x[1]]
i <- 1
while (total < 40){
     i <- i + 1
     total <- total + mydat$count[x[i]]
}

print(mydat$group[x[1:i]])

Göran


> I want to select   group ID randomly (without replacement)  until  the
> sum of count reaches 40.
> So, in  the first case, the data frame could be
>     G4 31
>     65 10
> 
> In other case, it could be
>    G5 10
>    G2 15
>    G3 12
> 
> How do I put sum of count variable   is  a minimum of 40 restriction?
> 
> Than k you in advance
> 
> 
> 
> 
> 
> 
> I want to select group  ids randomly until I reach the
> 
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