subset within a subset in R dplyr

Question

I need to remove several rows that meet a condition within a subset.

For instance, using the iris dataset, I would like to remove all the rows in which Sepal.Width = 3.2, but only within setosa

I have tried this: filter(iris, !Species %in% "setosa" & !Sepal.Width==3.2) But his removes all rows containing setosaand all rows in which Sepal.Width==3.2, rather than considering both conditions at the same time (i.e. only remove the rows of the condition within ‘setosa’ and leave the rest

General point: if you construct the correct condition, filter and analogues ([] and subset, for example) will all work and no subsetting of subsets is ever needed. In this case you could use !(x & y) as in SabDeM's answer, or the arguably less readable !x | !y — Frank
– Frank, Commented Jun 25, 2015 at 19:31
@Frank maybe I am wrong but I am thinking that I've learned such syntax !( <...conditions...> ) here on SO from you (or maybe another power user), because you commented my answer and made me realize the readability of it. As always thank you. — SabDeM
– SabDeM, Commented Jun 25, 2015 at 19:38
@fede_luppi I experienced the same thing with filter(), where it doesn't seem to properly honor boolean AND clauses for multiple criteria. I don't know why this is, and I feel better about myself that someone else has the issue... Anyway the way I solved it was to invert the criteria so it was constructed out of NOT's and OR's rather than an AND. Ugly and counterintuitive, but it worked. — Bob
– Bob, Commented Jun 25, 2015 at 22:29

SabDeM · Accepted Answer · 2015-06-25 19:35:12Z

Here is one way to do so with dplyr:

iris %>% filter(!(Sepal.Width == 3.2 & Species == "setosa"))

or in base R:

iris[!(iris$Species == "setosa" & iris$Sepal.Width == 3.2), ]

and last but not least, with subset:

subset(iris, !(Species == "setosa" & Sepal.Width == 3.2))

But I think that there are other ways to do such subsetting operations, example, with data table.

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