Use `Not` from `InvertedIndices` (this also gets imported with `DataFrames`):
```
julia> Y = collect(1:0.5:4)
7-element Vector{Float64}:
1.0
1.5
2.0
2.5
3.0
3.5
4.0
julia> x=rand(1:7, 3)
3-element Vector{Int64}:
3
2
6
julia> Y[Not(x)]
4-element Vector{Float64}:
1.0
2.5
3.0
4.0
```
Just out of curiosity I've taken a look at what happens under the hood, and I've used [dtruss/strace][1] on each test.
C++
./a.out < in
Saw 6512403 lines in 8 seconds. Crunch speed: 814050
syscalls `sudo dtruss -c ./a.out < in`
CALL COUNT
__mac_syscall 1
<snip>
open 6
pread 8
mprotect 17
mmap 22
stat64 30
read_nocancel 25958
Python
./a.py < in
Read 6512402 lines in 1 seconds. LPS: 6512402
syscalls `sudo dtruss -c ./a.py < in`
CALL COUNT
__mac_syscall 1
<snip>
open 5
pread 8
mprotect 17
mmap 21
stat64 29
[1]: http://en.wikipedia.org/wiki/Strace
