Get suffix from Vector of Vectors

New to Julia
1

Given is a vector of vectors

s = [[3, 2, 1, 1, 1],[3, 1, 2, 1, 3]]

where all vectors have the same length and an index vector
i = [3,4]

Is there an easy way to get the subvectors of s, starting at index i.e. 3 to end for the first vector and 4 to end for the second, and so on?

In the example above, the result should be
s_suff = [[1,1,1], [1,3]]

I tried
s_suff = [s[i][p:end] for i in 1:length(s)]

Thanks

2

I think you were almost there (you needed p[i])

julia> s = [[3, 2, 1, 1, 1],[3, 1, 2, 1, 3]]
2-element Array{Array{Int64,1},1}:
 [3, 2, 1, 1, 1]
 [3, 1, 2, 1, 3]

julia> p = [3,4]
2-element Array{Int64,1}:
 3
 4

julia> [ s[i][p[i]:end] for i in 1:length(s) ]
2-element Array{Array{Int64,1},1}:
 [1, 1, 1]
 [1, 3]

ps: use backticks to mark the code, makes reading much easier.

5 Likes
3

Perhaps a slightly shorter/more readable version would be:

julia> s = [[3, 2, 1, 1, 1],[3, 1, 2, 1, 3]];

julia> p = [3,4];

julia> [ S[P:end] for (S,P) in zip(s,p) ]
2-element Array{Array{Int64,1},1}:
 [1, 1, 1]
 [1, 3]
1 Like