r - Returning a true value if it is a close match among different columns in r

Question

The data is as follows :

a <- c('id1','id2','id3','id4','id5')
b <- c(5,10,7,2,3)
d <- c(5.2,150,123,5,7)
e <- c(5.4,0,10,3,5)

df1 <- data.frame(a,b,d,e)

I want to create a new column in this data frame returning TRUE and FALSE. It should be true if all the values are within 5% difference of each other, else false.

For example, for 'id1' the values are 5,5.2,5.4 respectively for b,d and e column. So all these are within 5% of each other hence the new_col should be true. For 'id2' the values are 10,150,0 respectively for b,d and e column.So, they are not with 5% of each other, hence it should be false.

Desired Output

标签： r

Answer 1

This looks at 1.05 times the minimum values is less than the 0.95 times the maximum value for each of the rows. (I assumed that's what you meant by within %5 of each other.)

sapply(1:nrow(df1), function(i) (min(df1[i, 2:4]) * 1.05) > 
     (0.95 * max(df1[i, 2:4])))
# [1]  TRUE FALSE FALSE FALSE FALSE

---

Slightly different way to do the same.

sapply(1:nrow(df1), function(i) diff(range(df1[i, 2:4]) * 
    c(1.05, 0.95)) <= 0)
# [1]  TRUE FALSE FALSE FALSE FALSE