I was wondering if there’s a way to do this in a more explicit way. Something like: b=a(a1=1,a2=2,a3=3).
The reason would be readability (so one would know what the variables of the struct are without having to know the right order to put them in. So ideally, b=a(a3=3,a1=1,a2=2) would also work.
Is this supported or would it take a lot of code to achieve (like making some fancy functions)?
Also, any disadvantage of using mutable structs vs regular ones?
Thanks a lot!
I’d generally go with a struct over a mutable struct where possible, but it really depends on the application. Good idea to provide your type definitions with concrete field types as a first step: Performance Tips · The Julia Language. Most of that page is worth a good read if you want to get decent performance
I’m planning on using structs to avoid passing too many variables to functions and having messy code. All my variables will have very defined types. Would this be a good way to do it, performance-wise?
mutable struct thing
a::Float64
b::Array{StaticArrays.SVector{3,Float64}}
c::Array{StaticArrays.SVector{Int}} # this one can have 3 or 4 elements in the SArray. Not sure how to declare that
d::Array{Float64}
end
I think you’ll probably want to use Vector{T} instead of Array{T}, or explicitly specify the second type parameter (number of dimensions). E.g., Array{T, 3}.
Array{T}, as opposed to Array{T, N}, for some constant T and N, is this kind of type: Types · The Julia Language I’m not yet sure how do those work, but I suspect that using them as fields in a struct may lead to unintended effects.
On the other hand, maybe you just need Tuples? What are your requirements? If you want a better answer, you should probably say what is the problem you’re solving, and give more examples of the values that will be of the type you are seeking for.
Ah, so a::Vector{Union{ SVector{3,Int},SVector{4,Int} }}.
I’m working on a problem that solves equations on large meshes. The vector above contains indices of the nodes of each element in my mesh (which can be a tri or a quad, hence the 3 or 4 condition). I usually use this vector to list all nodes in an element (points[elements[n]], where points is a Vector of StaticArrays containing the x/y/z coordinates of each point, and elements is the Vector of StaticArrays I mentioned above.
Does the information change how I should go around doing this? I’ve been using Julia for a month now, so I’m sure I’m doing many things wrong =P.
Thanks!
I’m also new to Julia, but here’s an idea if you need speed:
Instead of a single Vector, use two Vectors: a Vector{SVector{3,Int}} and a Vector{SVector{4,Int}}. This would mean more code for you to write; but assuming there’s a lot of data in the Vector(s), I think iterating over two Vectors of simpler types would be faster than iterating over a single vector of a more complex type.
