[R] Extract

[Ebert,Timothy Aaron]

The desired result is odd.
1) It looks like the string is duplicated in the desired result. The first line of data has "15, xc, Ab",  and the desired result has "15, xc, Ab, 15, xc, Ab"
2) The example has S1 through S5, but the desired result has data for eight variables in the first line (not five).
3) The desired result has a different number of variables for each line.
4) Are you assuming that all missing data is at the end of the string? If there are 5 variables (S1 .... S5), do you know that "15, xc, Ab" is S1 = 15, S2 = 'xc', and S3 = 'Ab' rather than S2=15, S4='xc' and S5='Ab' ?

This isn't exactly what you asked for, but maybe I was confused somewhere. This approach puts string data into variables in order. In this approach one mixes string and numeric data. The string is not duplicated.

library(tidyr)

dat <- read.csv(text="Year,Sex,string
2002,F,15 xc Ab
2003,F,14
2004,M,18 xb 25 35 21
2005,M,13 25
2006,M,14 ac 256 AV 35
2007,F,11", header=TRUE, stringsAsFactors=FALSE)

# split the 'string' column based on spaces
dat_separated <- dat |>
  separate(string, into = paste0("S", 1:5), sep = " ",
           fill = "right", extra = "merge")

Tim


-----Original Message-----
From: R-help <r-help-bounces using r-project.org> On Behalf Of Val
Sent: Friday, July 19, 2024 12:52 PM
To: r-help using R-project.org (r-help using r-project.org) <r-help using r-project.org>
Subject: [R] Extract

[External Email]

Hi All,

I want to extract new variables from a string and add it to the dataframe.
Sample data is csv file.

dat<-read.csv(text="Year, Sex,string
2002,F,15 xc Ab
2003,F,14
2004,M,18 xb 25 35 21
2005,M,13 25
2006,M,14 ac 256 AV 35
2007,F,11",header=TRUE)

The string column has  a maximum of five variables. Some rows have all and others may not have all the five variables. If missing then  fill it with NA, Desired result is shown below,


Year,Sex,string, S1, S2, S3 S4,S5
2002,F,15 xc Ab, 15,xc,Ab, NA, NA
2003,F,14, 14,NA,NA,NA,NA
2004,M,18 xb 25 35 21,18, xb, 25, 35, 21
2005,M,13 25,13, 25,NA,NA,NA
2006,M,14 ac 256 AV 35, 14, ac, 256, AV, 35
2007,F,11, 11,NA,NA,NA,NA

Any help?
Thank you in advance.

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