R - Inserting variable number of spaces into postcode string - regex

I have a set of UK postcodes which need to be reformatted. They are made up of an incode and an outcode, where incode is of the form 'number letter letter' e.g. 2DB and the outcode is a combination of between 2 and 4 letters and numbers e.g. NW1 or SW10 or EC1A
Currently there is one space between the incode and outcode, but I need to reformat these so that the full postcode is 7 characters long e.g: ('-' stands for space)
NW1-2DB -> NW1-2DB (1 space between outcode and incode)
SW10-9NH -> SW109NH (0 spaces)
E1-6QL -> E1--6QL (2 spaces)
Data:
df <- data.frame("postcode"=c("NW1 2DB","SW10 9NH","E1 6QL"))
df
# postcode
# 1 NW1 2DB
# 2 SW10 9NH
# 3 E1 6QL
I have written a regex string to separate the outcode and incode, but couldn't find a way to add a variable number of spaces between them (this example just creates two spaces between outcode and incode).
require(dplyr)
df <- df %>% mutate(postcode_2sp = gsub('?(\\S+)\\s*?(\\d\\w{2})$','\\1 \\2', postcode)
To get around that I've tried to use mutate(),nchar() and rep():
df<-df %>%
mutate(outcode=gsub('?(\\S+)\\s*\\d\\w{2}$','\\1',postcode),
incode=gsub('\\S+\\s*?(\\d\\w{2})$','\\1',postcode)) %>%
mutate(out_length=nchar(outcode))%>%
mutate(postcode7=paste0(outcode,
paste0(rep(" ",4-out_length),collapse=""),
incode))
but get this error:
Error: invalid 'times' argument
without the last step to create postcode7 the df looks as follows:
df
# postcode outcode incode out_length
# 1 NW1 2DB NW1 2DB 3
# 2 SW10 9NH SW10 9NH 4
# 3 E1 6QL E1 6QL 2
And if I set the rep 'times' argument to a constant the code runs as expected (but doesn't do what I need it to do!)
df<-df %>%
mutate(outcode=gsub('?(\\S+)\\s*\\d\\w{2}$','\\1',postcode),
incode=gsub('\\S+\\s*?(\\d\\w{2})$','\\1',postcode)) %>%
mutate(out_length=nchar(outcode))%>%
mutate(postcode7=paste0(outcode,
paste0(rep(" ",4),collapse=""),
incode))
df
# postcode outcode incode out_length postcode7
# 1 NW1 2DB NW1 2DB 3 NW1 2DB
# 2 SW10 9NH SW10 9NH 4 SW10 9NH
# 3 E1 6QL E1 6QL 2 E1 6QL
Is there a way to make rep() accept a column as the times argument in a mutate? Or should I be looking at a totally different approach?
EDIT: I've just realised that I can use an if statement for each case of 2 characters, 3 characters or 4 characters in the outcode but that doesn't feel very elegant.

Have a look at the str_pad method from stringr package, which is suited for your case:
library(stringr)
df<-df %>%
mutate(outcode=gsub('?(\\S+)\\s*\\d\\w{2}$','\\1',postcode),
incode=gsub('\\S+\\s*?(\\d\\w{2})$','\\1',postcode)) %>%
mutate(out_length=nchar(outcode)) %>%
mutate(postcode7 = paste(outcode, str_pad(incode, 7-out_length), sep = ""))
df
# postcode outcode incode out_length postcode7
# 1 NW1 2DB NW1 2DB 3 NW1 2DB
# 2 SW10 9NH SW10 9NH 4 SW109NH
# 3 E1 6QL E1 6QL 2 E1 6QL

Another solution, using sprintf to format the output, and tidyr::extract for matching. This has the advantage of drastically simplifying both the pattern and the code for padding:
df %>%
extract(postcode, into = c('out', 'in'), '(\\S{2,4})\\s*(\\d\\w\\w)') %>%
mutate(postcode = sprintf('% -4s%s', out, `in`))
I do like the separate version posted above, but it requires that the postcodes are all separated by whitespace. In my experience this generally isn’t the case.

Using str_pad and separate:
library(dplyr)
library(tidyr)
library(stringr)
df %>%
separate(postcode, into = c("incode", "outcode"), remove = FALSE) %>%
mutate(
postcode8 = paste0(incode,
str_pad(outcode,
8 - nchar(incode), side = "left", pad = " ")))
# postcode incode outcode postcode8
# 1 NW1 2DB NW1 2DB NW1 2DB
# 2 SW10 9NH SW10 9NH SW10 9NH
# 3 E1 6QL E1 6QL E1 6QL

df%>%mutate(Postcode7=paste0(format(gsub('\\s.*$','',postcode),justify='left'),
format(gsub('^\\S+\\s','',postcode),justify='right')))

Related

R sets of coordinates extract from string

I'am trying to extract sets of coordinates from strings and change the format.
I have tried some of the stringr package and getting nowhere with the pattern extraction.
It's my first time dealing with regex and still is a little confusing to create a pattern.
There is a data frame with one column with one or more sets of coordinates.
The only pattern (the majority) separating Lat from Long is (-), and to separate one set of coordinates to another there is a (/)
Here is an example of some of the data:
ID Coordinates
1 3438-5150
2 3346-5108/3352-5120 East island, South port
3 West coast (284312 472254)
4 28.39.97-47.05.62/29.09.13-47.44.03
5 2843-4722/3359-5122(1H-2H-3H-4F)
Most of the data is in decimal degree, e.g. (id 1 is Lat 34.38 Lon 51.50), some others is in 00º00'00'', e.g. (id 4 is Lat 28º 39' 97'' Lon 47º 05' 62'')
I will need to make in a few steps
1 - Extract all coordinates sets creating a new row for each set of each record;
2 - Extract the text label of record to a new column, concatenating them;
3- Convert the coordinates from 00º00'00''(28.39.97) to 00.0000º (28.6769 - decimal dregree) so all coordinates are in the same format. I can easily convert if they are as numeric.
4 - Add dot (.) to separate the decimal degree values (from 3438 to 34.38) and add (-) to identify as (-34.38) south west hemisphere. All value must have (-) sign.
I'am trying to get something like this:
Step 1 and 2 - Extract coordinates sets and names
ID x y label
1 3438 5150
2 3346 5108 East island, South port
2 3352 5120 East island, South port
3 284312 472254 West coast
4 28.39.97 47.05.62
4 29.09.13 47.44.03
5 2843 4722 1H-2H-3H-4F
5 3359 5122 1H-2H-3H-4F
Step 3 - convert coordinates format to decimal degree (ID 4)
ID x y label
1 3438 5150
2 3346 5108 East island, South port
2 3352 5120 East island, South port
3 284312 472254 West coast
4 286769 471005
4 291536 470675
5 2843 4722 1H-2H-3H-4F
5 3359 5122 1H-2H-3H-4F
Step 4 - change display format
ID x y label
1 -34.38 -51.50
2 -33.46 -51.08 East island, South port
2 -33.52 -51.20 East island, South port
3 -28.43 -47.22 West coast
4 -28.6769 -47.1005
4 -29.1536 -47.0675
5 -28.43 -47.22 1H-2H-3H-4F
5 -33.59 -51.22 1H-2H-3H-4F
I have edit the question to better clarify my problems and change some of my needs. I realized that it was messy to understand.
So, has anyone worked with something similar?
Any other suggestion would be of great help.
Thank you again for the time to help.
Note: the first answers address the original asking of the question and the last answer addresses its current state. The data in data1 should be set appropriately for each solution.
The following should address your first question given the data you provided and the expected output (using dplyr and tidyr).
library(dplyr)
library(tidyr)
### Load Data
data1 <- structure(list(ID = 1:4, Coordinates = c("3438-5150", "3346-5108/3352-5120",
"2843-4722/3359-5122(1H-2H-3H-4F)", "28.39.97-47.05.62/29.09.13-47.44.03"
)), .Names = c("ID", "Coordinates"), class = "data.frame", row.names = c(NA,
-4L))
### This is a helper function to transform data that is like '1234'
### but should be '12.34', and leaves alone '12.34'.
### You may have to change this based on your use case.
div100 <- function(x) { return(ifelse(x > 100, x / 100, x)) }
### Remove items like "(...)" and change "12.34.56" to "12.34"
### Split into 4 columns and xform numeric value.
data1 %>%
mutate(Coordinates = gsub('\\([^)]+\\)', '', Coordinates),
Coordinates = gsub('(\\d+[.]\\d+)[.]\\d+', '\\1', Coordinates)) %>%
separate(Coordinates, c('x.1', 'y.1', 'x.2', 'y.2'), fill = 'right', sep = '[-/]', convert = TRUE) %>%
mutate_at(vars(matches('^[xy][.]')), div100) # xform columns x.N and y.N
## ID x.1 y.1 x.2 y.2
## 1 1 34.38 51.50 NA NA
## 2 2 33.46 51.08 33.52 51.20
## 3 3 28.43 47.22 33.59 51.22
## 4 4 28.39 47.05 29.09 47.44
The call to mutate modifies Coordinates twice to make substitutions easier.
Edit
A variation that uses another regex substitution instead of mutate_at.
data1 %>%
mutate(Coordinates = gsub('\\([^)]+\\)', '', Coordinates),
Coordinates = gsub('(\\d{2}[.]\\d{2})[.]\\d{2}', '\\1', Coordinates),
Coordinates = gsub('(\\d{2})(\\d{2})', '\\1.\\2', Coordinates)) %>%
separate(Coordinates, c('x.1', 'y.1', 'x.2', 'y.2'), fill = 'right', sep = '[-/]', convert = TRUE)
Edit 2: The following solution addresses the updated version of the question
The following solution does a number of transformations to transform the data. These are separate to make it a bit easier to think about (much easier relatively speaking).
library(dplyr)
library(tidyr)
data1 <- structure(list(ID = 1:5, Coordinates = c("3438-5150", "3346-5108/3352-5120 East island, South port",
"East coast (284312 472254)", "28.39.97-47.05.62/29.09.13-47.44.03",
"2843-4722/3359-5122(1H-2H-3H-4F)")), .Names = c("ID", "Coordinates"
), class = "data.frame", row.names = c(NA, -5L))
### Function for converting to numeric values and
### handles case of "12.34.56" (hours/min/sec)
hms_convert <- function(llval) {
nres <- rep(0, length(llval))
coord3_match_idx <- grepl('^\\d{2}[.]\\d{2}[.]\\d{2}$', llval)
nres[coord3_match_idx] <- sapply(str_split(llval[coord3_match_idx], '[.]', 3), function(x) { sum(as.numeric(x) / c(1,60,3600))})
nres[!coord3_match_idx] <- as.numeric(llval[!coord3_match_idx])
nres
}
### Each mutate works to transform the various data formats
### into a single format. The 'separate' commands then split
### the data into the appropriate columns. The action of each
### 'mutate' can be seen by progressively viewing the results
### (i.e. adding one 'mutate' command at a time).
data1 %>%
mutate(Coordinates_new = Coordinates) %>%
mutate(Coordinates_new = gsub('\\([^) ]+\\)', '', Coordinates_new)) %>%
mutate(Coordinates_new = gsub('(.*?)\\(((\\d{6})[ ](\\d{6}))\\).*', '\\3-\\4 \\1', Coordinates_new)) %>%
mutate(Coordinates_new = gsub('(\\d{2})(\\d{2})(\\d{2})', '\\1.\\2.\\3', Coordinates_new)) %>%
mutate(Coordinates_new = gsub('(\\S+)[\\s]+(.+)', '\\1|\\2', Coordinates_new, perl = TRUE)) %>%
separate(Coordinates_new, c('Coords', 'label'), fill = 'right', sep = '[|]', convert = TRUE) %>%
mutate(Coords = gsub('(\\d{2})(\\d{2})', '\\1.\\2', Coords)) %>%
separate(Coords, c('x.1', 'y.1', 'x.2', 'y.2'), fill = 'right', sep = '[-/]', convert = TRUE) %>%
mutate_at(vars(matches('^[xy][.]')), hms_convert) %>%
mutate_at(vars(matches('^[xy][.]')), function(x) ifelse(!is.na(x), -x, x))
## ID Coordinates x.1 y.1 x.2 y.2 label
## 1 1 3438-5150 -34.38000 -51.50000 NA NA <NA>
## 2 2 3346-5108/3352-5120 East island, South port -33.46000 -51.08000 -33.52000 -51.20000 East island, South port
## 3 3 East coast (284312 472254) -28.72000 -47.38167 NA NA East coast
## 4 4 28.39.97-47.05.62/29.09.13-47.44.03 -28.67694 -47.10056 -29.15361 -47.73417 <NA>
## 5 5 2843-4722/3359-5122(1H-2H-3H-4F) -28.43000 -47.22000 -33.59000 -51.22000 <NA>
We can use stringi. We create a . between the 4 digit numbers with gsub, use stri_extract_all (from stringi) to extract two digit numbers followed by a dot followed by two digit numbers (\\d{2}\\.\\d{2}) to get a list output. As the list elements have unequal length, we can pad NA at the end for those elements that have shorter length than the maximum length and convert to matrix (using stri_list2matrix). After converting to data.frame, changing the character columns to numeric, and cbind with the 'ID' column of the original dataset.
library(stringi)
d1 <- as.data.frame(stri_list2matrix(stri_extract_all_regex(gsub("(\\d{2})(\\d{2})",
"\\1.\\2", data1$Coordinates), "\\d{2}\\.\\d{2}"), byrow=TRUE), stringsAsFactors=FALSE)
d1[] <- lapply(d1, as.numeric)
colnames(d1) <- paste0(c("x.", "y."), rep(1:2,each = 2))
cbind(data1[1], d1)
# ID x.1 y.1 x.2 y.2
#1 1 34.38 51.50 NA NA
#2 2 33.46 51.08 33.52 51.20
#3 3 28.43 47.22 33.59 51.22
#4 4 28.39 47.05 29.09 47.44
But, this can also be done with base R.
#Create the dots for the 4-digit numbers
str1 <- gsub("(\\d{2})(\\d{2})", "\\1.\\2", data1$Coordinates)
#extract the numbers in a list with gregexpr/regmatches
lst <- regmatches(str1, gregexpr("\\d{2}\\.\\d{2}", str1))
#convert to numeric
lst <- lapply(lst, as.numeric)
#pad with NA's at the end and convert to data.frame
d1 <- do.call(rbind.data.frame, lapply(lst, `length<-`, max(lengths(lst))))
#change the column names
colnames(d1) <- paste0(c("x.", "y."), rep(1:2,each = 2))
#cbind with the first column of 'data1'
cbind(data1[1], d1)

R Wildcard data frame merging

I'm trying to merge a data frame and vector not by exact string matches in a column, but by wildcard string matches. To clarify, say you have this dataframe:
v <-data.frame(X1=c("AGTACAGT","AGTGAAGT","TGTA","GTTA","GAT","GAT"),X2=c(1,1,1,1,1,1))
# X1 X2
# 1 AGTACAGT 1
# 2 AGTGAAGT 2
# 3 TGTA 3
# 4 GTTA 4
# 5 GAT 5
# 6 GAT 6
I want to create a dataframe by creating a different color for every AGT.{3}GT,.{T|G}TA,GAT pattern, and creating a new column X3 that would show that color. So something like this:
# X1 X2 X3
# 1 AGTACAGT 1 "#FE7F01"
# 2 AGTGAAGT 2 "#FE7F01"
# 3 TGTA 3 "#FE7F00"
# 4 GTTA 4 "#FE7F00"
# 5 GAT 5 "#FE8002"
# 6 GAT 6 "#FE8002"
So far I am using this to create colors for each level, but I don't know how to count how many "wildcard levels" as opposed to singular levels there are:
x <- nlevels(v$X1)
x.colors2 <- colorRampPalette(brewer.pal(8,"Paired"))(x)
G <- data.frame("X1"=levels(v$X1),"X3"=x.colors2)
v <- merge(v,G)
Here's a solution.
Find patterns:
pat <- c("^AGT.{3}GT$", "^.(T|G)TA$", "^GAT$")
n <- length(pat)
indList <- lapply(pat, grep, v$X1)
Generate colors:
library(RColorBrewer)
col <- colorRampPalette(brewer.pal(8, "Paired"))(n)
Add colors to data frame:
colFull <- rep(col, sapply(indList, length))
v$color <- colFull[order(unlist(indList))]
The result:
v
# X1 X2 color
# 1 AGTACAGT 1 #A6CEE3
# 2 AGTGAAGT 1 #A6CEE3
# 3 TGTA 1 #979C62
# 4 GTTA 1 #979C62
# 5 GAT 1 #FF7F00
# 6 GAT 1 #FF7F00

How to replicate column-names, split them at delimiter '/', into multiple column-names, in R?

I have this matrix (it's big in size) "mymat". I need to replicate the columns that have "/" in their column name matching at "/" and make a "resmatrix". How can I get this done in R?
mymat
a b IID:WE:G12D/V GH:SQ:p.R172W/G c
1 3 4 2 4
22 4 2 2 4
2 3 2 2 4
resmatrix
a b IID:WE:G12D IID:WE:G12V GH:SQ:p.R172W GH:SQ:p.R172G c
1 3 4 4 2 2 4
22 4 2 2 2 2 4
2 3 2 2 2 2 4
Find out which columns have the "/" and replicate them, then rename. To calculate the new names, just split on / and replace the last letter for the second name.
# which columns have '/' in them?
which.slash <- grep('/', names(mymat), value=T)
new.names <- unlist(lapply(strsplit(which.slash, '/'),
function (bits) {
# bits[1] is e.g. IID:WE:G12D and bits[2] is the V
# take bits[1] and replace the last letter for the second colname
c(bits[1], sub('.$', bits[2], bits[1]))
}))
# make resmat by copying the appropriate columns
resmat <- cbind(mymat, mymat[, which.slash])
# order the columns to make sure the names replace properly
resmat <- resmat[, order(names(resmat))]
# put the new names in
names(resmat)[grep('/', names(resmat))] <- sort(new.names)
resmat looks like this
# a b c GH:SQ:p.R172G GH:SQ:p.R172W IID:WE:G12D IID:WE:G12V
# 1 1 3 4 2 2 4 4
# 2 22 4 4 2 2 2 2
# 3 2 3 4 2 2 2 2
You could use grep to get the index of column names with / ('nm1'), replicate the column names in 'nm1' by using sub/scan to create 'nm2'. Then, cbind the columns that are not 'nm1', with the replicated columns ('nm1'), change the column names with 'nm2', and if needed order the columns.
#get the column index with grep
nm1 <- grepl('/', names(df1))
#used regex to rearrange the substrings in the nm1 column names
#removed the `/` and use `scan` to split at the space delimiter
nm2 <- scan(text=gsub('([^/]+)(.)/(.*)', '\\1\\2 \\1\\3',
names(df1)[nm1]), what='', quiet=TRUE)
#cbind the columns that are not in nm1, with the replicate nm1 columns
df2 <- cbind(df1[!nm1], setNames(df1[rep(which(nm1), each= 2)], nm2))
#create another index to find the starting position of nm1 columns
nm3 <- names(df1)[1:(which(nm1)[1L]-1)]
#we concatenate the nm3, nm2, and the rest of the columns to match
#the expected output order
df2N <- df2[c(nm3, nm2, setdiff(names(df1)[!nm1], nm3))]
df2N
# a b IID:WE:G12D IID:WE:G12V GH:SQ:p.R172W GH:SQ:p.R172G c
#1 1 3 4 4 2 2 4
#2 22 4 2 2 2 2 4
#3 2 3 2 2 2 2 4
data
df1 <- structure(list(a = c(1L, 22L, 2L), b = c(3L, 4L, 3L),
`IID:WE:G12D/V` = c(4L,
2L, 2L), `GH:SQ:p.R172W/G` = c(2L, 2L, 2L), c = c(4L, 4L, 4L)),
.Names = c("a", "b", "IID:WE:G12D/V", "GH:SQ:p.R172W/G", "c"),
class = "data.frame", row.names = c(NA, -3L))

R Merging 4 Strings into 1 String

I'm searching for the locations of 4 different substrings in x and trying to merge these four outputs into one cumulative string:
x <- ("AAABBADSJALKACCWIEUADD")
outputA <- gregexpr(pattern = "AAA", x)
outputB <- gregexpr(pattern = "ABB", x)
outputC <- gregexpr(pattern = "ACC", x)
outputD <- gregexpr(pattern = "ADD", x)
I would like to merge these four outputs and output this merged result as a text file with each element separated on new line.
merged_output
# 1
# 3
# 13
# 20
Thank you
Actually you can do it all at once using a lookahead (?=)
gregexpr("A(?=AA|BB|CC|DD)", x, perl=T)[[1]]
# [1] 1 3 13 20
# attr(,"match.length")
# [1] 1 1 1 1
# attr(,"useBytes")
# [1] TRUE
For example
library(stringi)
cat("merged_output",
paste("#",
stri_locate_first_fixed(pattern = c("AAA", "ABB", "ACC", "ADD"), ("AAABBADSJALKACCWIEUADD"))[, "start"]),
file = tf <- tempfile(fileext = ".txt"),
sep = "\n")
Now, the file named in tf contains
> merged_output
> # 1
> # 3
> # 13
> # 20
Not very automated, but
cat(paste(c(outputA[[1]][1], outputB[[1]][1], outputC[[1]][1], outputD[[1]][1]),
collapse = "\n"),
file = "outputfile.txt")
should do it.

split string without loss of characters

I wish to split strings at a certain character while retaining that character in the second resulting string. I can achieve almost all of the desired operation, except that I lose the characters I specify in strsplit, which I guess is called the delimiter.
Is there a way to request that strsplit retain the delimiter? Or must I use a regular expression of some kind? Thank you for any advice. This seems like a very basic question. Sorry if it is a duplicate. I prefer to use base R.
Here is an example showing what I have so far:
my.table <- read.table(text = '
model npar AICc
AA(~region+state+county+city)BB(~region+state+county+city)CC(~1) 17 11111.11
AA(~region+state+county)BB(~region+state+county)CC(~123) 14 22222.22
AA(~region+state)BB(~region+state)CC(~33) 13 33333.33
AA(~region)BB(~region)CC(~4321) 6 44444.44
', header = TRUE, stringsAsFactors = FALSE)
desired.result <- read.table(text = '
model CC npar AICc
AA(~region+state+county+city)BB(~region+state+county+city) CC(~1) 17 11111.11
AA(~region+state+county)BB(~region+state+county) CC(~123) 14 22222.22
AA(~region+state)BB(~region+state) CC(~33) 13 33333.33
AA(~region)BB(~region) CC(~4321) 6 44444.44
', header = TRUE, stringsAsFactors = FALSE)
split.model <- strsplit(my.table$model, 'CC\\(')
split.models <- matrix(unlist(split.model), ncol=2, byrow=TRUE, dimnames = list(NULL, c("model", "CC")))
desires.result2 <- data.frame(split.models, my.table[,2:ncol(my.table)])
desires.result2
# model CC npar AICc
# 1 AA(~region+state+county+city)BB(~region+state+county+city) ~1) 17 11111.11
# 2 AA(~region+state+county)BB(~region+state+county) ~123) 14 22222.22
# 3 AA(~region+state)BB(~region+state) ~33) 13 33333.33
# 4 AA(~region)BB(~region) ~4321) 6 44444.44
The basic idea is to use look-around operations from regular expressions to strsplit to get your desired result. However, it's a bit trickier than that with strsplit and positive lookahead. Read this excellent post from #JoshO'Brien for explanation.
pattern <- "(?<=\\))(?=CC)"
strsplit(my.table$model, pattern, perl=TRUE)
# [[1]]
# [1] "AA(~region+state+county+city)BB(~region+state+county+city)"
# [2] "CC(~1)"
# [[2]]
# [1] "AA(~region+state+county)BB(~region+state+county)"
# [2] "CC(~123)"
# [[3]]
# [1] "AA(~region+state)BB(~region+state)" "CC(~33)"
# [[4]]
# [1] "AA(~region)BB(~region)" "CC(~4321)"
Of course, I leave the task of do.call(rbind, ...) and cbind to get the final desired.output to you.
Almost right after I posted I thought of using gsub to insert a space and then split on the space. Although, I like Arun's answer better.
my.table <- read.table(text = '
model npar AICc
AA(~region+state+county+city)BB(~region+state+county+city)CC(~1) 17 11111.11
AA(~region+state+county)BB(~region+state+county)CC(~123) 14 22222.22
AA(~region+state)BB(~region+state)CC(~33) 13 33333.33
AA(~region)BB(~region)CC(~4321) 6 44444.44
', header = TRUE, stringsAsFactors = FALSE)
my.table$model <- gsub("CC", " CC", my.table$model)
split.model <- strsplit(my.table$model, ' ')
split.models <- matrix(unlist(split.model), ncol=2, byrow=TRUE, dimnames = list(NULL, c("model", "CC")))
desires.result <- data.frame(split.models, my.table[,2:ncol(my.table)])
desires.result
# model CC npar AICc
# 1 AA(~region+state+county+city)BB(~region+state+county+city) CC(~1) 17 11111.11
# 2 AA(~region+state+county)BB(~region+state+county) CC(~123) 14 22222.22
# 3 AA(~region+state)BB(~region+state) CC(~33) 13 33333.33
# 4 AA(~region)BB(~region) CC(~4321) 6 44444.44
... why not just tack the separator back on afterwards? Would seem to save a lot of trouble fiddling with regexes.
split.model <- lapply(strsplit(my.table$model, 'CC\\('), function(x) {
x[2] <- paste0("CC(", x[2])
x
})