3

Is there a way to remove rows from a dataframe, based on the column of another dataframe?

For example, Dataframe 1: 

        Gene CHROM    POS REF ALT N_INFORMATIVE     Test       Beta       SE
AAA     1  15211   T   G          1481  1:15211 -0.0599805 0.112445
LLL     1 762061   T   A          1481 1:762061  0.2144100 0.427085
CCC     1 762109   C   T          1481 1:762109  0.2847510 0.204255
DDD     1 762273   G   A          1481 1:762273  0.0443946 0.119924

Dataframe 2 (only 1 column): 

Genes
AAA
BBB
CCC
DDD
EEE
FFF

In this situtation, I want to scan Dataframe 1, column 1 for any matches to Dataframe 2, and remove matching rows.

They need to be an exact match, and the result would look like this: 

        Gene CHROM    POS REF ALT N_INFORMATIVE     Test       Beta       SE
LLL     1 762061   T   A          1481 1:762061  0.2144100 0.427085

I've tried variations of this, but it hasn't worked: 

NewDataframe <-!(Dataframe1$Gene==Dataframe2$Genes)

Thanks for reading.

mfk534
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1 Answers1

9

Use %in% to identify which elements from the first data frame are not contained in the second data frame, then pass the resulting logical vector to the first data frame to subset. 

dat1 <- data.frame(id = LETTERS[1:10], stringsAsFactors = FALSE)
dat2 <- data.frame(id = c("B", "D"), stringsAsFactors = FALSE)
dat1[!dat1$id %in% dat2$id, , drop = FALSE]
#    id
# 1   A
# 3   C
# 5   E
# 6   F
# 7   G
# 8   H
# 9   I
# 10  J
dayne
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