Change data.frame values to %

Question

How can I replace the values of a df which contains NA values, to the percentage of the contribution to the sum of the row?

Example:

# dummy df
a <- c("x","y","z")
b <- c(10,5,2)
c <- c("NA",1,"NA")
d <- c("NA",4,8)

dummy <- data.frame(a,b,c,d)

	a	b	c
x	10	NA	NA
y	5	1	4
z	2	NA	8

What I want:

	a	b	c
x	100%	NA	NA
y	50%	10%	40%
z	20%	NA	80%

Answer 1

First, it's better to use explicit NAs and not strings that say "NA".

Second, you can solve this using dplyr's rowwise() and across() :

library(scales)
library(dplyr)

# dummy df with explict NAs
a <- c("x","y","z")
b <- c(10,5,2)
c <- c(NA,1, NA)
d <- c(NA, 4,8)
dummy <- data.frame(a,b,c,d)
  
dummy %>% 
  # add column of sum by row
  rowwise() %>% 
  mutate(row_sum = sum(c_across(b:d), na.rm = TRUE),
         # divide each column by sum of row
         across(b:d, ~ percent(.x / row_sum))) %>% 
  ungroup() %>% 
  # remove sum column
  select(-row_sum)

#  A tibble: 3 x 4
#   a     b     c     d    
#   <chr> <chr> <chr> <chr>
# 1 x     100%  NA    NA   
# 2 y     50%   10%   40%  
# 3 z     20%   NA    80% 

Answer 2

You can simply do,

cbind.data.frame(dummy[1], 10 * (dummy[-1]))

#  a   b  c  d
#1 x 100 NA NA
#2 y  50 10 40
#3 z  20 NA 80

NOTE: Your columns must be numeric

Answer 3

You can also use this:

library(dplyr)

dummy %>%
  mutate(across(b:d, ~ ifelse(.x != "NA", paste0(as.numeric(.x) * 10, "%"), .x)))

  a    b   c   d
1 x 100%  NA  NA
2 y  50% 10% 40%
3 z  20%  NA 80%

Answer 4

i worked arround the problem by removing the first column, replacing the the NA with 0, doing the calculation and then reattaching the first column.

dummy[is.na(dummy)] <- 0 # sets na's as zeros

header <- dummy[1] # stores 1st column

df <- round(dummy[-1]/rowSums(dummy[-1])*100,digits=3) # calculates the %

df <- cbind(header,dummy) # joins 1st column to the results