Exclude elements of Array based on index (Julia)

The simplest way is to use "Not".

julia> using InvertedIndices # use ] add InvertedIndices if not installed

julia> A = [1,2,3,4,5,6,7,8]

julia> k = 4;

julia> A[Not(k)]
7-element Array{Int64,1}:
 1
 2
 3
 5
 6
 7
 8

Not as terse as the R equivalent, but fairly readable:

A[1:end .!= k]

More importantly, this can be used in multidimensional arrays too, e.g.

B[  1:end .!= i,   1:end .!= j,   1:end .!= k  ]

Have a look at deleteat!. Examples:

julia> A = [1,2,3,4,5,6,7,8]; k = 4;

julia> deleteat!(A, k)
7-element Array{Int64,1}:
 1
 2
 3
 5
 6
 7
 8

julia> A = [1,2,3,4,5,6,7,8]; k = 2:2:8;

julia> deleteat!(A, k)
4-element Array{Int64,1}:
 1
 3
 5
 7