CODEWITHSUNDEEP
r
jkatam
jkatam

Reputation: 3447

derive multiple columns from multiple columns in r

Consider that we have the below data and would like to derive variables z1,z2,z3 from x1y1, x2y2 and x3*y3.

could you please help me how i can achieve this in R

x1 <- c(1,2,3,4,5,6)
x2 <- c(2,3,4,5,6,7)
x3 <- c(3,4,5,6,7,8)
x4 <- c('A','B','C','D','E','F')
y1 <- c(1,2,3,4,5,6)
y2 <- c(2,3,4,5,6,7)
y3 <- c(3,4,5,6,7,8)

testa <- data.frame(x1,x2,x3,x4,y1,y2,y3)

array on multiple variables

Upvotes: 0

Views: 35

Answers (2)

akrun
akrun

Reputation: 886948

If we want to do this automatically, a tidyverse option is

library(dplyr)
library(stringr)
testa <- testa %>% 
   mutate(across(x1:x3,  ~ .x * get(str_replace(cur_column(), "x",
        "y")), .names = "{str_replace(.col, 'x', 'z')}"))

-output

testa
  x1 x2 x3 x4 y1 y2 y3 z1 z2 z3
1  1  2  3  A  1  2  3  1  4  9
2  2  3  4  B  2  3  4  4  9 16
3  3  4  5  C  3  4  5  9 16 25
4  4  5  6  D  4  5  6 16 25 36
5  5  6  7  E  5  6  7 25 36 49
6  6  7  8  F  6  7  8 36 49 64

Upvotes: 1

user10917479
user10917479

Reputation:

Assuming the integrity of your structure and naming conventions, you can select the x and y variables, multiple them together as a group, and then assign back to z.

var_i <- 1:3

testa[paste0("z", var_i)] <- testa[paste0("x", var_i)] * testa[paste0("y", var_i)]

  x1 x2 x3 x4 y1 y2 y3 z1 z2 z3
1  1  2  3  A  1  2  3  1  4  9
2  2  3  4  B  2  3  4  4  9 16
3  3  4  5  C  3  4  5  9 16 25
4  4  5  6  D  4  5  6 16 25 36
5  5  6  7  E  5  6  7 25 36 49
6  6  7  8  F  6  7  8 36 49 64

Upvotes: 1

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