I have two dataframes that look like this:
library(tibble)
df_1 <- tibble(id = c(1,1,1,2,2,2,3,3,3), y = c("a", "b", "c", "a", "b","c", "a", "b", "c"))
df_2 <- tibble(id = c(1,3), z = c(4,6))
I want to merge the two dfs such that it looks like this:
df_3 <- tibble(id = c(1,1,1,2,2,2,3,3,3), y = c("a", "b", "c", "a", "b","c", "a", "b", "c"), z = c(4,4,4,NA,NA,NA,6,6,6))
How will you do so in R? Thank you!
library(dplyr)
left_join(df_1,df_2)
Output:
id y z
<dbl> <chr> <dbl>
1 1 a 4
2 1 b 4
3 1 c 4
4 2 a NA
5 2 b NA
6 2 c NA
7 3 a 6
8 3 b 6
9 3 c 6
Related
I have a data frame, which looks like this:
DF_A <- data.frame(
Group_1 = c("A", "A", "A", "A", "A", "B", "B", "B", "B", "C"),
Group_2 = c("A", "B", "C", "A", "B", "A", "B", "A", "C", "A")
)
I would like to assign a consecutive number for Group_1 IDs which should be unique for the case of identical Group_2 IDs. For example, A+A starts with 1, A+B proceeds with 2 (same Group_1 ID, but new Group_2 ID), ..., A+A is again 1 (obviously a repetition). B+A is 1 (new Group_1 ID), ..., B+A (same Group_1 ID, but new Group_2 ID)...and so forth.
The result should look like this.
DF_B <- data.frame(
Group_1 = c("A", "A", "A", "A", "A", "B", "B", "B", "B", "C"),
Group_2 = c("A", "B", "C", "A", "B", "A", "B", "A", "C", "A"),
ID = c(1, 2, 3, 1, 2, 1, 2, 1, 1, 1)
)
I investigated various posts on corresponding approaches such as single groups within groups, or a combination - without any success - this case is not covered by previous posts.
Thank you in advance.
One way to do it with ave is
DF_A$ID <- ave(DF_A$Group_2, DF_A$Group_1, FUN = function(x) match(x, unique(x)))
DF_A
# Group_1 Group_2 ID
#1 A A 1
#2 A B 2
#3 A C 3
#4 A A 1
#5 A B 2
#6 B A 1
#7 B B 2
#8 B A 1
#9 B C 3
#10 C A 1
The equivalent dplyr way is :
library(dplyr)
DF_A %>%
group_by(Group_1) %>%
mutate(ID = match(Group_2, unique(Group_2)))
You can split into groups by Group_1, then create factor out of your combinations within each group then convert into integer
DF_A$ID <- unlist(by(DF_A, DF_A$Group_1, function(x) as.integer(factor(x$Group_2))))
We can use the dense_rank from dplyr.
library(dplyr)
DF_A2 <- DF_A %>%
group_by(Group_1) %>%
mutate(ID = dense_rank(Group_2)) %>%
ungroup()
DF_A2
# # A tibble: 10 x 3
# Group_1 Group_2 ID
# <fct> <fct> <int>
# 1 A A 1
# 2 A B 2
# 3 A C 3
# 4 A A 1
# 5 A B 2
# 6 B A 1
# 7 B B 2
# 8 B A 1
# 9 B C 3
# 10 C A 1
You could use the integer values of the factor levels. We can simply wrap Group_2 in c() to drop the factor attribute.
within(DF_A, { ID = ave(c(Group_2), Group_1, FUN = c) })
# Group_1 Group_2 ID
# 1 A A 1
# 2 A B 2
# 3 A C 3
# 4 A A 1
# 5 A B 2
# 6 B A 1
# 7 B B 2
# 8 B A 1
# 9 B C 3
# 10 C A 1
I have a database with several columns ( >20) and 2 of these columns have the subject names. I would like to add another column with inside a number that identifies the combination of the two subjects.
Here is an example with only the 2 columns of names (I don't include the others for convenience):
ID1 ID2
A B
A C
A B
B C
A B
B A
C B
And here is what i would like to create:
ID1 ID2 CODE
A B 1
A C 2
A B 1
B C 3
A B 1
B A 1
C B 3
I am kind of new in R and I think it can be done with stringr but I am not sure how
Thanks for the help!
Simo
df$CODE <- as.integer(
factor(
apply(df, 1, function(x) paste0(sort(x), collapse = ""))
)
)
# ID1 ID2 CODE
# 1 A B 1
# 2 A C 2
# 3 A B 1
# 4 B C 3
# 5 A B 1
# 6 B A 1
# 7 C B 3
Data
df <- data.frame(
ID1 = c("A", "A", "A", "B", "A", "B", "C"),
ID2 = c("B", "C", "B", "C", "B", "A", "B")
)
Try this:
library(dplyr)
#Code
new <- df %>% rowwise() %>%
mutate(Var = paste0(sort(c(ID1, ID2)), collapse = '')) %>%
group_by(Var) %>%
mutate(CODE=cur_group_id()) %>%
ungroup() %>%
select(-Var)
Output:
# A tibble: 7 x 3
ID1 ID2 CODE
<chr> <chr> <int>
1 A B 1
2 A C 2
3 A B 1
4 B C 3
5 A B 1
6 B A 1
7 C B 3
Some data used:
#Data
df <- structure(list(ID1 = c("A", "A", "A", "B", "A", "B", "C"), ID2 = c("B",
"C", "B", "C", "B", "A", "B")), class = "data.frame", row.names = c(NA,
-7L))
I have a dataset which is of the following form:-
a <- data.frame(X1=c("A", "B", "C", "A", "B", "C"),
X2=c("B", "C", "C", "A", "A", "B"),
X3=c("B", "E", "A", "A", "A", "B"),
X4=c("E", "C", "A", "A", "A", "C"),
X5=c("A", "C", "C", "A", "B", "B")
)
And I have another set of the following form:-
b <- data.frame(col_1=c("ASD", "ASD", "BSD", "BSD"),
col_2=c(1, 1, 1, 1),
col_3=c(12, 12, 31, 21),
col_4=("A", "B", "B", "A")
)
What I want to do is to take the column col_4 from set b and match row wise in set a, so that it tell me which row has how many elements from col_4 in a new column. The name of the new column does not matters.
For ex:- The first and fifth row in set a has all the elements of col_4 from set b.
Also, duplicates shouldn't be found. For ex. sixth row in set a has 3 "B"s. But since col_4 from set b has only two "B"s, it should tell me 2 and not 3.
Expected output is of the form:-
c <- data.frame(X1=c("A", "B", "C", "A", "B", "C"),
X2=c("B", "C", "C", "A", "A", "B"),
X3=c("B", "E", "A", "A", "A", "B"),
X4=c("E", "C", "A", "A", "A", "C"),
X5=c("A", "C", "C", "A", "B", "B"),
found=c(4, 1, 2, 2, 4, 2)
)
We can use vecsets::vintersect which takes care of duplicates.
Using apply row-wise we can count how many common values are there between b$col4 and each row in a.
apply(a, 1, function(x) length(vecsets::vintersect(b$col_4, x)))
#[1] 4 1 2 2 4 2
An option using data.table:
library(data.table)
#convert a into a long format
m <- melt(setDT(a)[, rn:=.I], id.vars="rn", value.name="col_4")
#order by row number and create an index for identical occurrences in col_4
setorder(m, rn, col_4)[, vidx := rowid(col_4), rn]
#create a similar index for b
setDT(b, key="col_4")[, vidx := rowid(col_4)]
#count occurrences and lookup this count into original data
a[b[m, on=.(col_4, vidx), nomatch=0L][, .N, rn], on=.(rn), found := N]
output:
X1 X2 X3 X4 X5 rn found
1: A B B E A 1 4
2: B C E C C 2 1
3: C C A A C 3 2
4: A A A A A 4 2
5: B A A A B 5 4
6: C B B C B 6 2
Another idea to operate on sets efficiently is to count and compare the element occurences of b$col_4 in each row of a:
b1 = c(table(b$col_4))
#b1
#A B
#2 2
a1 = table(factor(as.matrix(a), names(b1)), row(a))
#a1
#
# 1 2 3 4 5 6
# A 2 0 2 5 3 0
# B 2 1 0 0 2 3
Finally, identify the least amount of occurences per element (for each row) and sum:
colSums(pmin(a1, b1))
#1 2 3 4 5 6
#4 1 2 2 4 2
In case of a larger dimension a "data.frame" and more elements, Matrix::sparseMatrix offers an appropriate alternative:
library(Matrix)
a.fac = factor(as.matrix(a), names(b1))
.i = as.integer(a.fac)
.j = c(row(a))
noNA = !is.na(.i) ## need to remove NAs manually
.i = .i[noNA]
.j = .j[noNA]
a1 = sparseMatrix(i = .i, j = .j, x = 1L, dimnames = list(names(b1), 1:nrow(a)))
a1
#2 x 6 sparse Matrix of class "dgCMatrix"
# 1 2 3 4 5 6
#A 2 . 2 5 3 .
#B 2 1 . . 2 3
colSums(pmin(a1, b1))
#1 2 3 4 5 6
#4 1 2 2 4 2
I have a data frame, which looks like this:
DF_A <- data.frame(
Group_1 = c("A", "A", "A", "A", "A", "B", "B", "B", "B", "C"),
Group_2 = c("A", "B", "C", "A", "B", "A", "B", "A", "C", "A")
)
I would like to assign a consecutive number for Group_1 IDs which should be unique for the case of identical Group_2 IDs. For example, A+A starts with 1, A+B proceeds with 2 (same Group_1 ID, but new Group_2 ID), ..., A+A is again 1 (obviously a repetition). B+A is 1 (new Group_1 ID), ..., B+A (same Group_1 ID, but new Group_2 ID)...and so forth.
The result should look like this.
DF_B <- data.frame(
Group_1 = c("A", "A", "A", "A", "A", "B", "B", "B", "B", "C"),
Group_2 = c("A", "B", "C", "A", "B", "A", "B", "A", "C", "A"),
ID = c(1, 2, 3, 1, 2, 1, 2, 1, 1, 1)
)
I investigated various posts on corresponding approaches such as single groups within groups, or a combination - without any success - this case is not covered by previous posts.
Thank you in advance.
One way to do it with ave is
DF_A$ID <- ave(DF_A$Group_2, DF_A$Group_1, FUN = function(x) match(x, unique(x)))
DF_A
# Group_1 Group_2 ID
#1 A A 1
#2 A B 2
#3 A C 3
#4 A A 1
#5 A B 2
#6 B A 1
#7 B B 2
#8 B A 1
#9 B C 3
#10 C A 1
The equivalent dplyr way is :
library(dplyr)
DF_A %>%
group_by(Group_1) %>%
mutate(ID = match(Group_2, unique(Group_2)))
You can split into groups by Group_1, then create factor out of your combinations within each group then convert into integer
DF_A$ID <- unlist(by(DF_A, DF_A$Group_1, function(x) as.integer(factor(x$Group_2))))
We can use the dense_rank from dplyr.
library(dplyr)
DF_A2 <- DF_A %>%
group_by(Group_1) %>%
mutate(ID = dense_rank(Group_2)) %>%
ungroup()
DF_A2
# # A tibble: 10 x 3
# Group_1 Group_2 ID
# <fct> <fct> <int>
# 1 A A 1
# 2 A B 2
# 3 A C 3
# 4 A A 1
# 5 A B 2
# 6 B A 1
# 7 B B 2
# 8 B A 1
# 9 B C 3
# 10 C A 1
You could use the integer values of the factor levels. We can simply wrap Group_2 in c() to drop the factor attribute.
within(DF_A, { ID = ave(c(Group_2), Group_1, FUN = c) })
# Group_1 Group_2 ID
# 1 A A 1
# 2 A B 2
# 3 A C 3
# 4 A A 1
# 5 A B 2
# 6 B A 1
# 7 B B 2
# 8 B A 1
# 9 B C 3
# 10 C A 1
I'm looking to obtain a subset of my first, larger, dataframe 'df1' by selecting rows which contain particular combinations in the first two variables, as specified in a smaller 'df2'. For example:
df1 <- data.frame(ID = c("A", "A", "A", "B", "B", "B"),
day = c(1, 2, 2, 1, 2, 3), value = seq(4,9))
df1 # my actual df has 20 varables
ID day value
A 1 4
A 2 5
A 2 6
B 1 7
B 2 8
B 3 9
df2 <- data.frame(ID = c("A", "B"), day = c(2, 1))
df2 # this df remains at 2 variables
ID day
A 2
B 1
Where the output would be:
ID day value
A 2 5
A 2 6
B 1 7
Any help wouldbe much appreciated, thanks!
This is a good use of the merge function.
df1 <- data.frame(ID = c("A", "A", "A", "B", "B", "B"),
day = c(1, 2, 2, 1, 2, 3), value = seq(4,9))
df2 <- data.frame(ID = c("A", "B"), day = c(2, 1))
merge(df1,
df2,
by = c("ID", "day"))
Which gives output:
ID day value
1 A 2 5
2 A 2 6
3 B 1 7
Here is a dplyr solution:
library("dplyr")
semi_join(df1, df2, by = c("ID", "day"))
# ID day value
# 1 A 2 5
# 2 A 2 6
# 3 B 1 7