I made data frame called x:
a b 1 2 3 NA 3 32 21 7 12 8 When I run
y <- x["a">2,] The object y returned is identical to x. If I run
y <- x["a" == 1,] y is an empty frame.
I made sure that the names of the x data frame have no white spaces (I named them myself with names() ) and also that a and are numeric.
PS: If I try
y <- x["a">2] y is also returned as identical to x.
You're making an error in referencing the column of your data.frame x.
"a">2 means character a bigger than two, not variable a of data.frame x. You need to add either x$a or x["a"] to reference your data.frame column.
try
y <- x[x$a >2 ,]
or
y <- x[x["a"] >2 ,]
or even more clear
ix <- x["a"] > 2 y <- x[ix,] A simple alternative would be using data.table
library(data.table) setDT(x) y <- x[ a > 2, ] y <- x[ a == 1, ] 
