在R的for循环中使用粘贴函数编写ifelse语句

Question

So I have 50 variables with value range from 1 to 4, and I want to count how many are 1 or 2 and how many are 3 or 4.

ie abc1=2, abc2=2, ... abc50=3

and the following is my code

#Create new variable to store the counted number to

abc.low=0
abc.high=0

And here is the code I am stuck at (it doesn't work)

for (i in 1:50){
ifelse (paste("abc",i,sep="")==1|paste("abc",i,sep="")==2, 
(abc.low<-abc.low<-1),(abc.low<-abc.low))
}

for (i in 1:50){
ifelse (paste("abc",i,sep="")==3|paste("abc",i,sep="")==4, 
(abc.high<-abc.high<-1),(abc.high<-abc.high))
}

I am assuming the paste function is not appropriate in what I am trying to do.

ie)

abc1=3

abc1==3
#True

paste("abc",1,sep="")==3
# False

where the paste function should return true for my purpose.

I appreciate your input!

Answer 1

Try this for example:

table(unlist(mget(paste0('abc',1:50))))

• mget create a list of variable that unlist transform it a to a vector.

• table gives the occurrence of each value for example:

    1 2 3 4 14 13 13 10 

Answer 2

This will help you:

groups = rbinom(32, n = 50, prob = 0.4)
tapply(groups, groups, length)

Above tapply function returns count of elements in groups