sum some specific variables value in r

Question

I select some specific variables using grep() to do some other calculations that failed. I then created a new variable consisting of variables name and "+", not sum of the value.

# create a df
test <- data.frame(I60_freq_t = 1,
                   I60_freq_man = 1,
                   I60_freq_woman = 1,
                   I60_freq_lo65 = 1,
                   I60_freq_hi65 = 1,
                   I61_freq_t = 1,
                   I61_freq_man = 1,
                   I61_freq_woman = 1,
                   I61_freq_lo65 = 1,
                   I61_freq_hi65 = 1,
                   I62_freq_t = 1,
                   I62_freq_man = 1,
                   I62_freq_woman = 1,
                   I62_freq_lo65 = 1,
                   I62_freq_hi65 = 1
                   )

# extract variables with different end words and use " + " to concatenate
end_with_t <- grep('t$', names(test), value = T) %>% paste(collapse = '+')
end_with_man <- grep('[^a-z]man$', names(test), value = T) %>% paste(collapse = '+')
end_with_woman <- grep('woman$', names(test), value = T) %>% paste(collapse = '+')
end_with_lo65 <- grep('lo65$', names(test), value = T) %>% paste(collapse = '+')
end_with_hi65 <- grep('hi65$', names(test), value = T) %>% paste(collapse = '+')

# sum the value 
test2 <- test %>% mutate(t = end_with_t,
                         man = end_with_man,
                         woman = end_with_woman,
                         lo65 = end_with_lo65,
                         hi65 = end_with_hi65) 
# **** What I want is sum the value not sum the variables names *********

My questions are:

1.How can I revise my code to get what I want?

2.Are there better ways to do this?

Any help will be highly appreciated!!!

Take a look at mutate_at and use contains/ends/starts_with or write a function and map it to your data. What is your expected output, does collapse really sum? — NelsonGon
– NelsonGon, Commented Jun 19, 2019 at 14:56
@NelsonGon, no paste with collapse = "+" just creates strings with a plus character "+" between elements. — Gregor Thomas
– Gregor Thomas, Commented Jun 19, 2019 at 15:02
@NelsonGon， I want to sum the value. For example , new variable should like this t = 3 — zhiwei li
– zhiwei li, Commented Jun 20, 2019 at 2:43

www · Accepted Answer · 2019-06-19 15:02:25Z

2

Here is one idea using map_dfc to loop through the variable names and add them all together using rowSums. ends_with is a way to select the variables based on the end of a string.

library(tidyverse)

variables <- c("_t", "_man", "_woman", "_lo65", "_hi65")

test2 <- map_dfc(variables, ~test %>% 
          select(ends_with(.x)) %>%
          rowSums()) %>%
  setNames(str_remove(variables, fixed("_")))

test2
# A tibble: 1 x 5
      t   man woman  lo65  hi65
  <dbl> <dbl> <dbl> <dbl> <dbl>
1     3     3     3     3     3

answered Jun 19, 2019 at 15:02

www

39.3k12 gold badges52 silver badges94 bronze badges

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

Collectives™ on Stack Overflow

sum some specific variables value in r

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related