CODEWITHSUNDEEP
r
Vedda
Vedda

Reputation: 7435

Find smallest value with tolerance

How would you find the last lowest value in this vector with a certain tolerance without changing the order?

Example:

c(0, 785, 10273, 6231, 5417, 2328, 5249, 1725, 2656, 6258, 2687, 
2651, 1063, 325, 2556, 738, 631, 140, 57, 1173, 407, 225, 135, 
69, 81, 21, 16, 3, 0, 26, 1, 2, 0, 1, 2, 1, 1, 0, 0, 3, 1, 0, 
0, 0, 1, 0, 0, 0, 0, 1, 0)

Assume a tolerance of 26. Working backwards from the last element (0) I would like to return the position of the number with tolerance greater than 26 from the previous number. In this example it would be position 30, or the number 26.

Upvotes: 2

Views: 111

Answers (2)

thelatemail
thelatemail

Reputation: 93823

You can use Position with the right=TRUE argument to avoid having to search forwards and then take the last result:

Position(identity, diff(x) >= 26, right=TRUE) + 1
#[1] 30

Upvotes: 5

bgoldst
bgoldst

Reputation: 35314

If I understand your question correctly, you can do this:

tail(which(diff(x)>=26),1L)+1L;
## [1] 30

Data

x <- c(0,785,10273,6231,5417,2328,5249,1725,2656,6258,2687,2651,1063,325,2556,738,631,140,57,
1173,407,225,135,69,81,21,16,3,0,26,1,2,0,1,2,1,1,0,0,3,1,0,0,0,1,0,0,0,0,1,0);

Upvotes: 2

Related Questions