SuiteSparse.jl VS Fortran-code-on-GitHub

Julia's compiler is made to be extendable. GPUCompiler.jl which adds the .ptx compilation output for example is a package (https://github.com/JuliaGPU/GPUCompiler.jl). The package manager of Julia itself... is an external package (https://github.com/JuliaLang/Pkg.jl). The built in SuiteSparse usage? That's a package too (https://github.com/JuliaLang/SuiteSparse.jl). It's fairly arbitrary what is "external" and "internal" in a language that allows that kind of extendability. Literally the only thing that makes these packages a standard library is that they are built into and shipped with the standard system image. Do you want to make your own distribution of Julia that changes what the "internal" packages are? Here's a tutorial that shows how to add plotting to the system image (https://julialang.github.io/PackageCompiler.jl/dev/examples/...). You could setup a binary server for that and now the first time to plot is 0.4 seconds.

Julia's arrays system is built so that most arrays that are used are not the simple Base.Array. Instead Julia has an AbstractArray interface definition (https://docs.julialang.org/en/v1/manual/interfaces/#man-inte...) which the Base.Array conforms to, and many effectively standard library packages like StaticArrays.jl, OffsetArrays.jl, etc. conform to, and thus they can be used in any other Julia package, like the differential equation solvers, solving nonlinear systems, optimization libraries, etc. There is a higher chance that packages depend on these packages then that they do not. They are only not part of the Julia distribution because the core idea is to move everything possible out to packages. There's not only a plan to make SuiteSparse and sparse matrix support be a package in 2.0, but also ideas about making the rest of linear algebra and arrays themselves into packages where Julia just defines memory buffer intrinsic (with likely the Arrays.jl package still shipped with the default image). At that point, are arrays not built into the language? I can understand using such a narrow definition for systems like Fortran or C where the standard library is essentially a fixed concept, but that just does not make sense with Julia. It's inherently fuzzy.

The hints in place ("there is more infrastructure already available outside Fortran, consider using them instead"). Beliavsky's compilation Fortran code on GitHub with its section about neural networks and machine learning still may be worth a visit e.g. how let Fortran reach out for the implementations in other languages.

There is an interesting directories compiled about projects around Fortran, Fortran code on GitHub. Though artificial intelligence does not appear by name, section Neural networks and Machine Learning may provide an entry.

My list of Fortran codes on GitHub has a section Containers and Generic Programming with some of the data structures you mention.

There's modern stuff being written in astro(nomy/physics) (I can attest to some of the codebases listed in https://github.com/Beliavsky/Fortran-code-on-GitHub#astrophy... being modern, at least in terms of development), but I'd say C++ likely does have the upper hand for newer codebases (unless things have changed dramatically last time I looked, algorithms that don't nicely align with nd-arrays are still painful in Fortran).

I've also heard rumours of Julia and even Rust being used (the latter because of the ability to reuse libraries in the browser e.g. for visualisation), but the writers of these codebases (and the Fortran/C/C++/Java) are unusual—Python and R (and for some holdouts, IDL) are what are most people write in (even if those languages call something else).

"QuantEcon:Open source code for economic modeling" https://quantecon.org/ has Python and Julia versions. The Federal Reserve uses Julia in its macroeconomic models: https://frbny-dsge.github.io/DSGE.jl/latest/ . Some economists use Fortran (which is much modernized since FORTRAN 77), and there is a 2018 book Introduction to Computational Economics using Fortran https://www.ce-fortran.com/ . Some Fortran codes in economics, statistics, and time series analysis are listed at https://github.com/Beliavsky/Fortran-code-on-GitHub .

At the "Fortran Code on GitHub" repo https://github.com/Beliavsky/Fortran-code-on-GitHub there are many codes listed in the "Climate and Weather" and "Earth Science" sections.

Fortran 77 and later versions (most recently Fortran 2018) have strings. There is the limitation that the elements of an array of strings must have equal length, so that ["boy","girl"] is invalid but ["boy ","girl"] is. Libraries for manipulating strings in Fortran are listed at https://github.com/Beliavsky/Fortran-code-on-GitHub#strings .