apply function to each element of a list nested r

Question

I have a function like this:

a <- list()
a$prod_1 <- c(1,2,3)
a$prod_2 <- c(4,5,6)

and I want to exponentiante each element of the list I tried something like this:

exp_a <- lapply(a, funtion(x) e^x)

What is your expected output? lapply(a, exp) will return a list of exponentiated vectors. — johnckane
– johnckane, Commented Apr 23, 2020 at 15:19

AlexR · Accepted Answer · 2020-04-23 15:22:08Z

1

e doesn't exist as a constant in R, but the exponential function does.
Just use exp_a <- lapply(a, exp)

answered Apr 23, 2020 at 15:22

AlexR

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2 Comments

I would like to use a customized function like 10 ^x

What is the problem then? lapply(a, function(x)10^x) will do that. Or do you need a different return format?

ThomasIsCoding · Accepted Answer · 2020-04-23 15:26:19Z

1

You have a couple of ways to make it, while below are just two examples:

exp_a <- Map(exp,a)

or

exp_a <- as.list(as.data.frame(exp(do.call(cbind,a))))

answered Apr 23, 2020 at 15:26

ThomasIsCoding

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akrun · Accepted Answer · 2020-04-23 18:33:21Z

0

We can use map from purrr

library(purrr)
map(a, exp)

answered Apr 23, 2020 at 18:33

akrun

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