[R] Filtering data with dplyr or grep and losing data?

Satish Vadlamani @@ti@h@v@dl@m@ni @ending from gm@il@com
Wed Dec 19 21:13:28 CET 2018

Hello Experts:

I have this log file that has about 1200 characters (max) on a line. What I
want to do is read this first and then extract certain portions of the file
into new columns. I want to extract rows that contain the text “[DF_API:
input string]”. When I read it and then filter based on the rows that I am
interested, it almost seems like I am losing data. I tried this using the
dplyr filter and using standard grep with the same result.

Not sure why this is the case. Appreciate your help with this. The code and
the data is there at the following link. Satish

Code is given below


sec1 <- read.delim(file="secondary1_aa_small.log")
names(sec1) <- c("V1")
sec1_test <- filter(sec1,str_detect(V1,"DF_API: input string")==TRUE)

sec1_test2 = sec1[grep("DF_API: input string",sec1$V1, perl = TRUE),]

write.csv(sec1_test, file = "test_out.txt", row.names = F, quote = F)
write.csv(sec1_test2, file = "test2_out.txt", row.names = F, quote = F)

Data (and code) is given at the link below. Sorry, I should have used dput.


Satish Vadlamani

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