R manipulating data by a row

Question

Consider following data frame:

R
df1<-
data.frame(
ostan=rep( paste("ostan",1:3),each=12),
year=rep(c(2020,2021),each=6,len=36),
month=rep(c(1:3),each=2,len=36),
ENF=rep(letters[1:2],len=36),
Fo=1:36,
JA=36:1
,KH=c(1:12,12:1,21:32)
)

The variables "Fo", "JA" and "KH" are frequencies of some events. I want to calculate these frequencies for each values of variable "ENF" as follows:

Consider this is a test data! The real data have too many labels in "ENF" column. The output should be a data frame.

Answer 1

You can use the following solution. This output is close to what you are looking for as R's data frames cannot have multiple headers, however, we could of course use package kableExtra to produce a table with multiple headers:

library(tidyr)

df1 %>%
  pivot_wider(names_from = ENF, 
              values_from = c(Fo, JA, KH), 
              names_glue = "{ENF}_{.value}")

# A tibble: 18 x 9
   ostan    year month  a_Fo  b_Fo  a_JA  b_JA  a_KH  b_KH
   <chr>   <dbl> <int> <int> <int> <int> <int> <int> <int>
 1 ostan 1  2020     1     1     2    36    35     1     2
 2 ostan 1  2020     2     3     4    34    33     3     4
 3 ostan 1  2020     3     5     6    32    31     5     6
 4 ostan 1  2021     1     7     8    30    29     7     8
 5 ostan 1  2021     2     9    10    28    27     9    10
 6 ostan 1  2021     3    11    12    26    25    11    12
 7 ostan 2  2020     1    13    14    24    23    12    11
 8 ostan 2  2020     2    15    16    22    21    10     9
 9 ostan 2  2020     3    17    18    20    19     8     7
10 ostan 2  2021     1    19    20    18    17     6     5
11 ostan 2  2021     2    21    22    16    15     4     3
12 ostan 2  2021     3    23    24    14    13     2     1
13 ostan 3  2020     1    25    26    12    11    21    22
14 ostan 3  2020     2    27    28    10     9    23    24
15 ostan 3  2020     3    29    30     8     7    25    26
16 ostan 3  2021     1    31    32     6     5    27    28
17 ostan 3  2021     2    33    34     4     3    29    30
18 ostan 3  2021     3    35    36     2     1    31    32

Or in base R we could do:

reshape(df1, direction = "wide", 
        idvar = c("ostan", "year", "month"),
        timevar = "ENF")