For simple cases there's also the IndirectArrays package: https://github.com/JuliaArrays/IndirectArrays.jl
Best, --Tim On Fri, Sep 30, 2016 at 10:51 PM, <[email protected]> wrote: > OK! many thanks for your fast reply > --a > > > On Friday, September 30, 2016 at 3:53:43 PM UTC+2, [email protected] > wrote: >> >> Hi guys, >> >> I'm learning the language while implementing an advanced package for >> geometric and solid modeling. >> My question is: What is the right idiom (shorter and/or faster) for >> writing this kind of array indexing: >> >> linesFromLineArray(V,EV) = Any[[V[:,EV[:,k][1]] V[:,EV[:,k][2]] ] for >> k=1:size(EV,2)] >> >> The efficiency is the strongest issue, since this method should provide >> the indirect indexing for any kind of cellular complexes. >> Many thanks for your help >> >> >> julia> V,EV >> ( >> 2x10 Array{Float64,2}: >> 0.13611 0.14143 0.38501 0.42103 0.96927 0.90207 0.0 0.11508 >> 0.61437 0.52335 >> 0.59824 0.58921 0.25964 0.24118 0.19741 0.34109 0.0213 0.0 >> 0.05601 0.17309, >> >> 2x5 Array{Int64,2}: >> 1 3 5 7 9 >> 2 4 6 8 10) >> >> julia> linesFromLineArray(V,EV) >> 5-element Array{Any,1}: >> 2x2 Array{Float64,2}: >> 0.13611 0.14143 >> 0.59824 0.58921 >> 2x2 Array{Float64,2}: >> 0.38501 0.42103 >> 0.25964 0.24118 >> 2x2 Array{Float64,2}: >> 0.96927 0.90207 >> 0.19741 0.34109 >> 2x2 Array{Float64,2}: >> 0.0 0.11508 >> 0.0213 0.0 >> 2x2 Array{Float64,2}: >> 0.61437 0.52335 >> 0.05601 0.17309 >> >>
