Removing mirrored combinations of variables in a data frame - r

I'm looking to get each unique combination of two variables:
library(purrr)
cross_df(list(id1 = seq_len(3), id2 = seq_len(3)), .filter = `==`)
# A tibble: 6 x 2
id1 id2
<int> <int>
1 2 1
2 3 1
3 1 2
4 3 2
5 1 3
6 2 3
How do I remove out the mirrored combinations? That is, I want only one of rows 1 and 3 in the data frame above, only one of rows 2 and 5, and only one of rows 4 and 6. My desired output would be something like:
# A tibble: 3 x 2
id1 id2
<int> <int>
1 2 1
2 3 1
3 3 2
I don't care if a particular id value is in id1 or id2, so the below is just as acceptable as the output:
# A tibble: 3 x 2
id1 id2
<int> <int>
1 1 2
2 1 3
3 2 3

A tidyverse version of Dan's answer:
cross_df(list(id1 = seq_len(3), id2 = seq_len(3)), .filter = `==`) %>%
mutate(min = pmap_int(., min), max = pmap_int(., max)) %>% # Find the min and max in each row
unite(check, c(min, max), remove = FALSE) %>% # Combine them in a "check" variable
distinct(check, .keep_all = TRUE) %>% # Remove duplicates of the "check" variable
select(id1, id2)
# A tibble: 3 x 2
id1 id2
<int> <int>
1 2 1
2 3 1
3 3 2

A Base R approach:
# create a string with the sorted elements of the row
df$temp <- apply(df, 1, function(x) paste(sort(x), collapse=""))
# then you can simply keep rows with a unique sorted-string value
df[!duplicated(df$temp), 1:2]

Related

Find rows that occur only once, in two datasets

I have data as follows:
library(data.table)
datA <- fread("A B C
1 1 1
2 2 2")
datB <- fread("A B C
1 1 1
2 2 2
3 3 3")
I want to figure out which rows are unique (which is the one with 3 3 3, because all others occur more often).
I tried:
dat <- rbind(datA, datB)
unique(dat)
!duplicated(dat)
I also tried
setDT(dat)[,if(.N ==1) .SD,]
But that is NULL.
How should I do this?
You can use fsetdiff:
rbind.data.frame(fsetdiff(datA, datB, all = TRUE),
fsetdiff(datB, datA, all = TRUE))
In general, this is called an anti_join:
library(dplyr)
bind_rows(anti_join(datA, datB),
anti_join(datB, datA))
A B C
1: 4 4 4
2: 3 3 3
Data: I added a row in datA to show how to keep rows from both data sets (a simple anti-join does not work otherwise):
library(data.table)
datA <- fread("A B C
1 1 1
2 2 2
4 4 4")
datB <- fread("A B C
1 1 1
2 2 2
3 3 3")
One possible solution
library(data.table)
datB[!datA, on=c("A", "B", "C")]
A B C
<int> <int> <int>
1: 3 3 3
Or (if you are interested in the symmetric difference)
funion(fsetdiff(datB, datA), fsetdiff(datA, datB))
A B C
<int> <int> <int>
1: 3 3 3
Another dplyr option by filtering rows that appear once with a group_by and filter:
library(data.table)
library(dplyr)
datA %>%
bind_rows(., datB) %>%
group_by(across(everything())) %>%
filter(n() == 1)
#> # A tibble: 1 × 3
#> # Groups: A, B, C [1]
#> A B C
#> <int> <int> <int>
#> 1 3 3 3
Created on 2022-11-09 with reprex v2.0.2

Function over tidyverse code results in issue with quotes

Example of the problem I'm having with applying a function including tidyverse code. I want to repeat for different variable names, but I'm not sure how to 'unquote'.
Example data:
df <- data.frame(grp=c(1,2,1,2,1), one=c(rep('a', 3), rep('b', 2)), two=c(rep('a', 1), rep('d', 4)))
cn <- colnames(df)[2:ncol(df)]
for(i in cn){
i <- enquo(i)
print(df %>% group_by(grp) %>% count(!!i))
}
# A tibble: 2 x 3
# Groups: grp [2]
grp `"one"` n
<dbl> <chr> <int>
1 1 one 3
2 2 one 2
# A tibble: 2 x 3
# Groups: grp [2]
grp `"two"` n
<dbl> <chr> <int>
1 1 two 3
2 2 two 2
Doing it for a single variable named one; this is the correct output.
df %>% group_by(grp) %>% count(one)
# A tibble: 4 x 3
# Groups: grp [2]
grp one n
<dbl> <fct> <int>
1 1 a 2
2 1 b 1
3 2 a 1
4 2 b 1
You can use map, also can avoid group_by by including grp in count
library(dplyr)
library(purrr)
map(cn, ~df %>% count(grp, .data[[.x]]))
#[[1]]
# grp one n
#1 1 a 2
#2 1 b 1
#3 2 a 1
#4 2 b 1
#[[2]]
# grp two n
#1 1 a 1
#2 1 d 2
#3 2 d 2
You can also use NSE with sym
map(cn, ~df %>% count(grp, !!sym(.x)))

Add original values for columns after group by

For the dataframe below I want to add the original values for Var_x after a group_by on ID and event and a max() on quest, but I cannot get my code right. Any suggestions? By the way, in my original dataframe more than 1 column needs to be added.
df <- data.frame(ID = c(1,1,1,1,1,1,2,2,2,3,3,3),
quest = c(1,1,2,2,3,3,1,2,3,1,2,3),
event = c("A","B","A","B","A",NA,"C","D","C","D","D",NA),
VAR_X = c(2,4,3,6,3,NA,6,4,5,7,5,NA))
Code:
df %>%
group_by(ID,event) %>%
summarise(quest = max(quest))
Desired output:
ID quest event VAR_X
1 1 2 B 6
2 1 3 A 3
3 2 2 D 4
4 2 3 C 5
5 3 2 D 5
Start by omiting the na values and in the end do an inner_join with the original data set.
df %>%
na.omit() %>%
group_by(ID, event) %>%
summarise(quest = max(quest)) %>%
inner_join(df, by = c("ID", "event", "quest"))
## A tibble: 5 x 4
## Groups: ID [3]
# ID event quest VAR_X
# <dbl> <fct> <dbl> <dbl>
#1 1 A 3 3
#2 1 B 2 6
#3 2 C 3 5
#4 2 D 2 4
#5 3 D 2 5
df %>%
drop_na() %>% # remove if necessary ..
group_by(ID, event) %>%
filter(quest == max(quest)) %>%
ungroup()
# A tibble: 5 x 4
# ID quest event VAR_X
#<dbl> <dbl> <chr> <dbl>
# 1 1 2 B 6
# 2 1 3 A 3
# 3 2 2 D 4
# 4 2 3 C 5
# 5 3 2 D 5

R add rows to grouped df using dplyr

I have a grouped df and I would like to add additional rows to the top of the groups that match with a variable (item_code) from the df.
The additional rows do not have an id column. The additional rows should not be duplicated within the groups of df.
Example data:
df <- as.tibble(data.frame(id=rep(1:3,each=2),
item_code=c("A","A","B","B","B","Z"),
score=rep(1,6)))
additional_rows <- as.tibble(data.frame(item_code=c("A","Z"),
score=c(6,6)))
What I tried
I found this post and tried to apply it:
Add row in each group using dplyr and add_row()
df %>% group_by(id) %>% do(add_row(additional_rows %>%
filter(item_code %in% .$item_code)))
What I get:
# A tibble: 9 x 3
# Groups: id [3]
id item_code score
<int> <fct> <dbl>
1 1 A 6
2 1 Z 6
3 1 NA NA
4 2 A 6
5 2 Z 6
6 2 NA NA
7 3 A 6
8 3 Z 6
9 3 NA NA
What I am looking for:
# A tibble: 6 x 3
id item_code score
<int> <fct> <dbl>
1 1 A 6
2 1 A 1
3 1 A 1
4 2 B 1
5 2 B 1
6 3 B 1
7 3 Z 6
8 3 Z 1
This should do the trick:
library(plyr)
df %>%
join(subset(df, item_code %in% additional_rows$item_code, select = c(id, item_code)) %>%
join(additional_rows) %>%
subset(!duplicated(.)), type = "full") %>%
arrange(id, item_code, -score)
Not sure if its the best way, but it works
Edit: to get the score in the same order added the other arrange terms
Edit 2: alright, there should now be no duplicated rows added from the additional rows as per your comment

Add missing subtotals to each group using dplyr

I need to add a new row to each id group where the key= "n" and value is the total - a + b
x <- data_frame( id = c(1,1,1,2,2,2,2),
key = c("a","b","total","a","x","b","total"),
value = c(1,2,10,4,1,3,12) )
# A tibble: 7 × 3
id key value
<dbl> <chr> <dbl>
1 1 a 1
2 1 b 2
3 1 total 10
4 2 a 4
5 2 x 1
6 2 b 3
7 2 total 12
In this example, the new rows should be
1 n 7
2 n 5
I tried getting the a+b subtotal and joining that to the total count to get the difference, but after using nine dplyr verbs I seem to be going in the wrong direction. Thanks.
This isn't a join, it's just binding new rows on:
x %>% group_by(id) %>%
summarize(
value = sum(value[key == 'total']) - sum(value[key %in% c('a', 'b')]),
key = 'n'
) %>%
bind_rows(x) %>%
select(id, key, value) %>% # back to original column order
arrange(id, key) # and a start a row order
# # A tibble: 9 × 3
# id key value
# <dbl> <chr> <dbl>
# 1 1 a 1
# 2 1 b 2
# 3 1 n 7
# 4 1 total 10
# 5 2 a 4
# 6 2 b 3
# 7 2 n 5
# 8 2 total 12
# 9 2 x 1
Here's a way using data.table, binding rows as in Gregor's answer:
library(data.table)
setDT(x)
dcast(x, id ~ key)[, .(id, key = "n", value = total - a - b)][, rbind(.SD, x)][order(id)]
id key value
1: 1 n 7
2: 1 a 1
3: 1 b 2
4: 1 total 10
5: 2 n 5
6: 2 a 4
7: 2 x 1
8: 2 b 3
9: 2 total 12

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