[R] A question of data frame filter based on another one

[Rui Barradas]

Hello,

Use ?rowSums and compare its result to 0. You want the sums greater than 
zero.


x <- "
   id  g
1  1 21
2  3 52
3  2 43
4  4 94
5  5 35"
y <- "
id g
1  1 1
2  0 0
3  0 1
4  1 0
5  1 0"

x <- read.table(textConnection(x), header = TRUE)
y <- read.table(textConnection(y), header = TRUE)

x[rowSums(x) > 0L, ]
#  id  g
#1  1 21
#2  3 52
#3  2 43
#4  4 94
#5  5 35


Hope this helps,

Rui Barradas

Às 18:32 de 18/02/2022, Li, Aiguo (NIH/NCI) [E] via R-help escreveu:
> I have tow dataframes as below:
>> x
>    id  g
> 1  1 21
> 2  3 52
> 3  2 43
> 4  4 94
> 5  5 35
> 
>> y
>    id g
> 1  1 1
> 2  0 0
> 3  0 1
> 4  1 0
> 5  1 0
> 
> Results dataframe I want is:
> 1 21
> 2 43
> 4 94
> 5 35
> 
> Basically I want to extract all the values in x which corresponding those values =1 in y.
> 
> I tried:
> x[which(y==1),].  It gets:
> id  g
> 1     1 21
> 4     4 94
> 5     5 35
> NA   NA NA
> NA.1 NA NA
> 
> But missing the row: 2 43.
> 
> Any help will be appreciated.
> 
> Thanks,
> Aiguo
> 
> 	[[alternative HTML version deleted]]
> 
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