Creating a variable with a function in R

Question

I want to regress the following equation: x5 = B0 + B1(x1-x2) + B2 * max[0,(x2 - x1)] + e

I have some trouble with generating the max[0,(x0 - x1)] variable. The variable should either be 0 if (x2-x1) is <0, or the difference between (x2-x1) if >=0.

 d1 <- structure(list(Date=c("2012-01-01", "2012-06-01",
                 "2013-01-01", "2013-06-01", "2014-01-01", "2014-06-01"),
                 x1=c(10, 12, 17L, 29L, 27L, 10L), 
                 x2=c(30L, 19L, 22L, 20L, 11L,24L), 
                 x3=c(28, 23L, 22L, 27L, 21L, 26L),
                 x4=c(30L, 28L, 23L,24L, 10L, 17L), 
                 x5=c(14, 17, 19, 16L, 30L, 26L)),
                 row.names=c(NA, 6L), class="data.frame")
 rownames(d1) <- d1[, "Date"]   
 d1 <- d1[,-1]

Thank you

Ronak Shah · Accepted Answer · 2019-04-04 08:11:35Z

3

We can use pmax

pmax(0, d1$x2 - d1$x1)
#[1] 20  7  5  0  0 14

This returns maximum between x2 - x1 or 0.

ifelse approach would be

ifelse(d1$x2 - d1$x1 < 0, 0, d1$x2 - d1$x1)
#[1] 20  7  5  0  0 14

answered Apr 4, 2019 at 8:11

Ronak Shah

391k20 gold badges173 silver badges237 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

markus Over a year ago

A third option for fun: with(d1, (x2 - x1) * ((x2 - x1) > 0))

Collectives™ on Stack Overflow

Creating a variable with a function in R

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related