Compare two columns for string and print "TRUE" or "FALSE"

Question

I have a df with two columns containing strings with false negative and false positive calls. I'd like to compare the two columns and identify the ones that are both "FN" and "FP" and make a third column with a "tag" indicating whether the columns meet the specs of the query.

For example here's a piece of the df

x1           x2
1/2:FN:am    .:.:.
1|1:FN:am    0/1:FP:am
.:.:.        1|0:559.511:FP

I'd like the resulting output to be

x1           x2               x3
1/2:FN:am    .:.:.            False
1|1:FN:am    0/1:FP:am        True
.:.:.        1|0:559.511:FP   False

Thanks!

I think the answer you are searching for is explained here: http://stackoverflow.com/a/10152029/7019856 — gima, Jan 10 '17 at 17:57
@gima I'm not seeing how this applies. There is no comparison between columns going in in this answer. — Stephen Williams, Jan 10 '17 at 18:11

score 3 · Answer 1 · answered Jan 10 '17 at 18:38

3

Does this give you what you need?

df <- data.frame(x1=c("1:FN:AM","1.2:FN:AM","3"),x2=c("1:AM","1.2:FP:AM","3"),stringsAsFactors = FALSE)
         x1        x2
1   1:FN:AM      1:AM
2 1.2:FN:AM 1.2:FP:AM
3         3         3

df$x3 <- sapply(df$x1,grepl,pattern = "FN") & sapply(df$x2,grepl,pattern = "FP")
         x1        x2    x3
1   1:FN:AM      1:AM FALSE
2 1.2:FN:AM 1.2:FP:AM  TRUE
3         3         3 FALSE

answered Jan 10 '17 at 18:38

PhilC

767
3
8

thanks! I'm not sure why people didn't care for the question but your answer was perfect. – Stephen Williams Jan 10 '17 at 18:51

score 1 · Answer 2 · answered Jan 10 '17 at 19:33

This also works (this captures any of the patterns (FP in x1 and FN in x2) or (FN in x1 and FP in x2))

df <- read.table(text='x1           x2
                 1/2:FN:am    .:.:.
                 1|1:FN:am    0/1:FP:am
                 1|0:55:FP    0/2:FN:am
                 .:.:.        1|0:559.511:FP', header=TRUE, stringsAsFactors=FALSE)
df$x3 <- grepl('.*FN.*FP.*|.*FP.*FN.*', paste(df$x1, df$x2))
df
#         x1             x2    x3
#1 1/2:FN:am          .:.:. FALSE
#2 1|1:FN:am      0/1:FP:am  TRUE
#3 1|0:55:FP      0/2:FN:am  TRUE
#4     .:.:. 1|0:559.511:FP FALSE

Compare two columns for string and print "TRUE" or "FALSE"

2 Answers2