Nice to see more plasma physicists using Julia. a=0.0 > You could just do a[:] = 0.0
to set all the elements to zero or you could do a=zeros(n) In regards to the negative indexing I think that while negative indexing may not be a part of base you should be able to replicate the effect with a package e.g. https://github.com/simonster/TwoBasedIndexing.jl
