1

I have a vector, 

x<-c(1,3,2,3,1,4,2,1,3,4,2,1,0,2,4,5,2,1,2)

I would like to obtain a vector of x by not including one every other time starting from the first element up to the 10th element. This will be to include elements (1,3,5,7 and 9 of x) to obtain (1,2,1,2,3). In line with the below expression which produces an error. 

x[1:10,by=2]

Thank you

Barnaby
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3 Answers3

6

You may use

x[seq(1, 10, by=2)]

In this way with seq(1, 10, by=2) you generate the indexes of x - elements and then you get them from x with [] operator.

cenka
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3

Here's another way could do this, although the above suggestions are more straight forward

x[1:10%%2 != 0][1:5]

Similar way (probably better) suggested by @SimonO'Hanlon

x[c(TRUE, FALSE)][1:5]
David Arenburg
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2

You can do this: 

x[seq(from=1,to=10, by=2)]
Daniel Falbel
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