negating using values !

[FIC]

when would you do this:

1. !(dataframe$columnA == 222 & dataframe$columnB == 1234)

vs.

2. (dataframe$columnA != 222 & dataframe$columnB !=1234)

[woodward]

dataframe <- data.frame(columnA=c(222,222,111,111), columnB=c(1234,9999,1234,9999))

dataframe
#>   columnA columnB
#> 1     222    1234
#> 2     222    9999
#> 3     111    1234
#> 4     111    9999

# this one gives all rows that are not row 1
!(dataframe$columnA == 222 & dataframe$columnB == 1234)
#> [1] FALSE  TRUE  TRUE  TRUE

# this one gives the intersection of rows 3-4 and rows 2,4
(dataframe$columnA != 222 & dataframe$columnB !=1234)
#> [1] FALSE FALSE FALSE  TRUE

^{Created on 2019-06-11 by the reprex package (v0.3.0)}