Find duplicates in comma-separated string data using R - r

Question

I am currently trying to run multiple data using loop, and ended up with the results below. Each line corresponds to the output from one data that has been filtered.
I am using this code to get the results below.
output <- print(paste(data.final$Peptide, collapse = ','))
It was previously given the form of table with one of the column name "Peptide", so I am pasting the peptide into a string separated comma, as shown here :
[1]"LPPAYTNSF,LPFNDGVYF,WMESEFRVY,YSSANNCTF,SANNCTFEY,KIYSKHTPI,WTAGAAAYY,YLQPRTFLL,CVADYSVLY,YNSASFSTF,ASFSTFKCY,RLFRKSNLK,TSNQVAVLY"
[1]"LPPAYTNSF,LPFNDGVYF,WMESEFRVY,YSSANNCTF,SANNCTFEY,KIYSKHTPI,WTAGAAAYY,YLQPRTFLL,CVADYSVLY,YNSASFSTF,ASFSTFKCY,RLFRKSNLK,QSYGFQPTY,TSNQVAVLY"
[1]"LPPAYTNSF,LPFNDGVYF,WMESEFRVY,YSSANNCTF,SANNCTFEY,KIYSKHTPI,WTAGAAAYY,YLQPRTFLL,CVADYSVLY,YNSASFSTF,ASFSTFKCY,RLFRKSNLK,QSYGFQPTY,TSNQVAVLY"
[1]"LPPAYTNSF,LPFNDGVYF,WMESEFRVY,YSSANNCTF,SANNCTFEY,KIYSKHTPI,WTAGAAAYY,YLQPRTFLL,CVADYSVLY,YNSASFSTF,ASFSTFKCY,RLFRKSNLK,QSYGFQPTY,TSNQVAVLY"
[1]"LPPAYTNSF,LPFNDGVYF,WMESEFRVY,YSSANNCTF,SANNCTFEY,KIYSKHTPI,WTAGAAAYY,YLQPRTFLL,CVADYSVLY,YNSASFSTF,ASFSTFKCY,RLFRKSNLK,QSYGFQPTY,TSNQVAVLY"
[1]"LPSAYTNSF,SAYTNSFTR,LPFNDGVYF,WMESEFRVY,YSSANNCTF,SANNCTFEY,KIYSKHTPI,WTAGAAAYY,YLQPRTFLL,CVADYSVLY,YNSASFSTF,ASFSTFKCY,RLFRKSNLK,QSYGFQPTY,TSNQVAVLY"
[1]"LPSAYTNSF,SAYTNSFTR,LPFNDGVYF,WMESEFRVY,YSSANNCTF,SANNCTFEY,KIYSKHTPI,WTAGAAAYY,YLQPRTFLL,CVADYSVLY,YNSASFSTF,ASFSTFKCY,RLFRKSNLK,QSYGFQPTY,TSNQVAVLY"
[1]"LPPAYTNSF,LPFNDGVYF,WMESEFRVY,YSSANNCTF,SANNCTFEY,KIYSKHTPI,WTAGAAAYY,YLQPRTFLL,CVADYSVLY,YNSASFSTF,ASFSTFKCY,RLFRKSNLK,TSNQVAVLY"
I would like to find the number of duplicates from each comma-separated strings (eg. LPPAYTNSF) between the lines.
Is there anyways to do this?

Answer 1

If I understand you well, there is no reason to first collapse them to a string. Why not just get the counts from your data.frame? Any n > 1 has duplicates.
data.final %>% count(Peptide)
solution based on your string
table(unlist(strsplit(v, ",")))
results
ASFSTFKCY CVADYSVLY KIYSKHTPI LPFNDGVYF LPPAYTNSF LPSAYTNSF QSYGFQPTY RLFRKSNLK SANNCTFEY SAYTNSFTR TSNQVAVLY WMESEFRVY
8 8 8 8 6 2 6 8 8 2 8 8
WTAGAAAYY YLQPRTFLL YNSASFSTF YSSANNCTF
8 8 8 8
data
v <- "LPPAYTNSF,LPFNDGVYF,WMESEFRVY,YSSANNCTF,SANNCTFEY,KIYSKHTPI,WTAGAAAYY,YLQPRTFLL,CVADYSVLY,YNSASFSTF,ASFSTFKCY,RLFRKSNLK,TSNQVAVLY,LPPAYTNSF,LPFNDGVYF,WMESEFRVY,YSSANNCTF,SANNCTFEY,KIYSKHTPI,WTAGAAAYY,YLQPRTFLL,CVADYSVLY,YNSASFSTF,ASFSTFKCY,RLFRKSNLK,QSYGFQPTY,TSNQVAVLY,LPPAYTNSF,LPFNDGVYF,WMESEFRVY,YSSANNCTF,SANNCTFEY,KIYSKHTPI,WTAGAAAYY,YLQPRTFLL,CVADYSVLY,YNSASFSTF,ASFSTFKCY,RLFRKSNLK,QSYGFQPTY,TSNQVAVLY,LPPAYTNSF,LPFNDGVYF,WMESEFRVY,YSSANNCTF,SANNCTFEY,KIYSKHTPI,WTAGAAAYY,YLQPRTFLL,CVADYSVLY,YNSASFSTF,ASFSTFKCY,RLFRKSNLK,QSYGFQPTY,TSNQVAVLY,LPPAYTNSF,LPFNDGVYF,WMESEFRVY,YSSANNCTF,SANNCTFEY,KIYSKHTPI,WTAGAAAYY,YLQPRTFLL,CVADYSVLY,YNSASFSTF,ASFSTFKCY,RLFRKSNLK,QSYGFQPTY,TSNQVAVLY,LPSAYTNSF,SAYTNSFTR,LPFNDGVYF,WMESEFRVY,YSSANNCTF,SANNCTFEY,KIYSKHTPI,WTAGAAAYY,YLQPRTFLL,CVADYSVLY,YNSASFSTF,ASFSTFKCY,RLFRKSNLK,QSYGFQPTY,TSNQVAVLY,LPSAYTNSF,SAYTNSFTR,LPFNDGVYF,WMESEFRVY,YSSANNCTF,SANNCTFEY,KIYSKHTPI,WTAGAAAYY,YLQPRTFLL,CVADYSVLY,YNSASFSTF,ASFSTFKCY,RLFRKSNLK,QSYGFQPTY,TSNQVAVLY,LPPAYTNSF,LPFNDGVYF,WMESEFRVY,YSSANNCTF,SANNCTFEY,KIYSKHTPI,WTAGAAAYY,YLQPRTFLL,CVADYSVLY,YNSASFSTF,ASFSTFKCY,RLFRKSNLK,TSNQVAVLY"

Answer 2

Not quite sure what your data are like so I've scribbled together some toy data to show how a regex and a non-regex tidyverse solution would work on your task of "find[ing] the number of duplicates from each comma-separated strings":
Data:
x <- c("a,c,x,a,f,s,w,s,b,n,x,q",
"A,B,B,X,B,Q")
A regex tidyverse solution:
library(tidyverse)
data.frame(x) %>%
# create new column with duplicated values:
mutate(dups = str_extract_all(x, "([A-Za-z])+(?=.*\\1)"))
x dups
1 a,c,x,a,f,s,w,s,b,n,x,q a, x, s
2 A,B,B,X,B,Q B, B
NB: the + in the regex pattern makes sure you can use this solution also for longer-than-one-character alphabetic comma-separated strings
Alternatively, a non-regex tidyverse solution:
library(tidyverse)
data.frame(x) %>%
# make column with unique ID for each string:
mutate(stringID = row_number()) %>%
# separate values into rows:
separate_rows(x) %>%
# for each combination of `stringID` and `x`...
group_by(stringID, x) %>%
# ...count the number of tokens:
summarise(N = n()) %>%
# show only the duplicated values:
filter(N > 1)
# A tibble: 4 × 3
# Groups: stringID [2]
stringID x N
<int> <chr> <int>
1 1 a 2
2 1 s 2
3 1 x 2
4 2 B 3