Operate only on a few components of a static vector

[lmiq]

SparseMatrix or SArray, MArray?

For convenience, yes, but this is what I mean: using StaticArrays, BenchmarkTools, Setfield function mut!(A) A .= A .+ 1 end Base.setindex!(m::SMatrix,value,i,j) = @set! m[i,j] = value A1 = rand(3,3) A2 = rand(MMatrix{3,3,Float64}) A3 = rand(SMatrix{3,3,Float64}) @btime mut!($A1) @btime mut!($A2) @btime mut!($A3) Results: 14.548 ns (0 allocations: 0 bytes) 4.733 ns (0 allocations: 0 bytes) 1.791 ns (0 allocations: 0 bytes) This actually makes me wonder how and why MMatrix …

Look at this. For longer vectors that changes? Is that the point?