Remove rows of a data frame if id is found in another list in R

Question

I have a data frame final where each observation has an id in a column called final$workerId I want to remove some rows of this data frame if their ID is found in another list called omit Here is what I've tried

final <- read.csv("the data.csv")
omit <- c("A3E9N7HDRLT8KV","A39HQTITNY9TVJ","A272A0JGRTBFCR","A1QPHQ1C27ZFI7")
final <- final[,-final$workerId %in% omit]

I know how I could do it with a for loop but I am looking for a solution without using for loops if possible

Answer 1

%in% returns a logical vector. The opposite of a logical vector can be found with !, not -, so final[!final$workerId %in% omit, ] is what you want.

You could also use which to turn your logical into an integer index vector, and then you could use - like this: final[-which(final$workerId %in% omit), ], but the first way seems simpler.

Example:

mtcars[!mtcars$cyl %in% c(4, 6), ]
                     mpg cyl  disp  hp drat    wt  qsec vs am gear carb
Hornet Sportabout   18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
Duster 360          14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
Merc 450SE          16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3
Merc 450SL          17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3
Merc 450SLC         15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3
Cadillac Fleetwood  10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4
Lincoln Continental 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4
Chrysler Imperial   14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4
Dodge Challenger    15.5   8 318.0 150 2.76 3.520 16.87  0  0    3    2
AMC Javelin         15.2   8 304.0 150 3.15 3.435 17.30  0  0    3    2
Camaro Z28          13.3   8 350.0 245 3.73 3.840 15.41  0  0    3    4
Pontiac Firebird    19.2   8 400.0 175 3.08 3.845 17.05  0  0    3    2
Ford Pantera L      15.8   8 351.0 264 4.22 3.170 14.50  0  1    5    4
Maserati Bora       15.0   8 301.0 335 3.54 3.570 14.60  0  1    5    8

Answer 2

here's a dplyr solution that may be of interest. The logic of the syntax is similar to the base R attempt you wrote in your question.

omit <- c("A3E9N7HDRLT8KV","A39HQTITNY9TVJ","A272A0JGRTBFCR","A1QPHQ1C27ZFI7")
final <- filter(final, !(workerId %in% omit))

dplyr's filter selects a subset of rows based on some condition. The condition we provide here is the set of character strings that are not (!) in (%in%) the vector omit. Because it's a dplyr function, you don't need to use the data frame name final when referencing the vector workerId after you call it in the first argument.