New to OCaml: How would I go about implementing Gaussian Elimination?

Question

I'm new to OCaml, and I'd like to implement Gaussian Elimination as an exercise. I can easily do it with a stateful algorithm, meaning keep a matrix in memory and recursively operating on it by passing around a reference to it.

This statefulness, however, smacks of imperative programming. I know there are capabilities in OCaml to do this, but I'd like to ask if there is some clever functional way I haven't thought of first.

Answer 1

OCaml arrays are mutable, and it's hard to avoid treating them just like arrays in an imperative language.

Haskell has immutable arrays, but from my (limited) experience with Haskell, you end up switching to monadic, mutable arrays in most cases. Immutable arrays are probably amazing for certain specific purposes. I've always imagined you could write a beautiful implementation of dynamic programming in Haskell, where the dependencies among array entries are defined entirely by the expressions in them. The key is that you really only need to specify the contents of each array entry one time. I don't think Gaussian elimination follows this pattern, and so it seems it might not be a good fit for immutable arrays. It would be interesting to see how it works out, however.