I have defined a type called CylindricalStress for bundling the results of Lamé’s Equations which I understand is good practice: struct CylindricalStress r::Number # Radial Stress θ::Number # Tangential (Hoop) Stress z::Number # Longitudinal Stress end """ lame(r, pᵢ, pₒ=0) Comput…

Solution to Question #1 [image] lmiq: Maybe FieldVector from StaticArrays … (although, as pointed above, some of the operations may not make sense - the norm being one of them. Others, like the sum, maybe?) You could start from that and overload some functions that you need with specific imp…

[image] Nathan_Boyer: 1. How can I define my type as a subtype of something else so I don’t have to extend every function manually? I just want this to act like any three-component vector for sum(σ) , mean(σ) , 10.*σ , norm.(σ) , etc. I think this is relevant: https://docs.julialang.org/en/…

[image] Nathan_Boyer: 3. How can I keep my type as a “private implementation detail”? I have heard the stance on this forum that custom types should not be publicly available. Why is that and how would that be implemented in this case? I’m not sure what you’re referring to here. Can you give…

[image] Nathan_Boyer: Why is that and how would that be implemented in this case? I think this is not a particular concern in general. Just not export the types, if the user doesn’t have to access them directly.

[image] Nathan_Boyer: 2. What types should I enforce in the struct and in the function ? I have heard you need AbstractVector in order to accept a slice, and that you can’t restrict to Number if you want to accept Uniful.jl types. AbstractVector or AbstractArray (depending on whether you act…

[image] rdeits: I’m not sure what you’re referring to here. Can you give an example? Reference for question #3: [image] Documenting elements of a struct New to Julia I agree that struct fields should be considered implementation details unless specified otherwise, b…

[image] rdeits: Also, I think you’ve been misinformed about Number and Unitful : Reference for question #2: [image] Are generic types worth the complexity? General Usage It’s worth it to at least annotate argument types as AbstractVector or alike. Because it won’t b…

Fields being private unless indicated otherwise is just a convention, not something enforced by the language. Cf the custom of not entering someone else’s home without being invited in, even if the door is unlocked.

Perhaps you can help us understand the implementation more. To calculate the norm of your CylidricalStress, is it just the euclidian norm of the elements? Or are there other calculations involved, given one is the radial stress, one is the longitudinal stress?

Sorry, I don’t mean “How do I enforce privacy?”. I am wondering how you can get away with not explaining your types to the user? Define every possible function they could want to use it with in the package, and make sure those functions return only Base types?

I think the key thing is whether or not it is iterable. If you define iteration for your type, (which is easy), then std, var, sum, etc. all intuitively make sense to the user, and don’t need to be overloaded or documented. Since its the same behavior as the docstring for sum(::Any) which exists in …

Basic struct usage questions

New to Julia

Nathan_Boyer September 29, 2021, 1:59pm 10

Reference for question #2:

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StaticArrays, parametric types, type stability General Usage parametric-types , type-stability , staticarrays	7	644	April 13, 2021
Arrays of abstract types within a parametric type Internals & Design type , parametric-types	17	1494	April 21, 2022
Structs and parametric constructors New to Julia	25	2868	December 19, 2018
Why [1, 2, 3] is not a Vector{Number}? New to Julia question , parametric-types	41	7222	December 9, 2022
Why is it impossible to subtype a struct? General Usage	29	11188	January 23, 2019

Basic struct usage questions

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