perkot
perkot

Reputation: 121

calculate percentage of total for multiple columns

I have a data-frame in R with several columns that contribute to a totals column, as per below:

data <- data_frame(
Date = c("14/12/2018", "15/12/2018", "16/12/2018"),
Ent = c("C1", "C1", "C1"),
Ans = c(4, 9, 12),
Aban = c(1, 2, 1),
OOH = c(7, 5, 6),
Total = c(12, 16, 19),
)

Output below:

Date       Ent     Ans  Aban   OOH Total
<chr>      <chr> <dbl> <dbl> <dbl> <dbl>
14/12/2018 C1        4     1     7    12
15/12/2018 C1        9     2     5    16
16/12/2018 C1       12     1     6    19

What I am wanting to do is find the most efficient way that I can calculate the percentage contribution of each column to the total. Below I have my current solution which requires three separate lines of code:

#Ans
data$AnsP <- (data$Ans / data$Total) * 100

#Aban
data$AbanP <- (data$Aban / data$Total) * 100

#OOH
data$OOHP <- (data$OOH / data$Total) * 100

However, as I anticipate the source data-set to grow, this will eventually become sub-optimal for multiple variables

Is there an easy way I can calculate these percentage contributions in a single line of code, returning these percentages as columns in the existing dataframe? Perhaps with sapply or a function? I have made some crude attempts, but they have not worked

Desire Output as a dataframe:

Date       Ent     Ans  Aban   OOH Total  AnsP AbanP  OOHP
<chr>      <chr> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
14/12/2018 C1        4     1     7    12  33.3  8.33  58.3
15/12/2018 C1        9     2     5    16  56.2 12.5   31.2
16/12/2018 C1       12     1     6    19  63.2  5.26  31.6

Any assistance would be appreciated on this

Regards, Tom

Upvotes: 2

Views: 5277

Answers (2)

akrun
akrun

Reputation: 887118

We can use data.table to assign in place

library(data.table)
setDT(data)[, paste0(names(data)[3:5], '_P') := lapply(.SD, function(x) 
        x/Total * 100), .SDcols = 3:5]
data
#         Date Ent Ans Aban OOH Total    Ans_P    Aban_P    OOH_P
#1: 14/12/2018  C1   4    1   7    12 33.33333  8.333333 58.33333
#2: 15/12/2018  C1   9    2   5    16 56.25000 12.500000 31.25000
#3: 16/12/2018  C1  12    1   6    19 63.15789  5.263158 31.57895

Upvotes: 3

Ronak Shah
Ronak Shah

Reputation: 388982

With dplyr

library(dplyr)

data %>%
   mutate_at(vars(Ans:OOH) , funs(P = ./data$Total * 100))


#   Date       Ent     Ans  Aban   OOH Total Ans_P Aban_P OOH_P
#  <chr>      <chr> <dbl> <dbl> <dbl> <dbl> <dbl>  <dbl> <dbl>
#1 14/12/2018 C1        4     1     7    12  33.3   8.33  58.3
#2 15/12/2018 C1        9     2     5    16  56.2  12.5   31.2
#3 16/12/2018 C1       12     1     6    19  63.2   5.26  31.6

Or if you prefer base R

cols <- 3:5
cbind(data, data[cols]/data$Total * 100)

As Total column is same as sum of cols column we could also do

data[cols]/rowSums(data[cols]) * 100

Upvotes: 4

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