Are there sites for discussing more informally about computational modelling?
Forum-style, rather than QA.
There are a couple of resources I know worth trying; however, in my opinion, they either lack the focus or do not have the required audience.
There is also a classic example of a science-focused forum in Russian that is still very alive:
Generally, the era of social media and SE "killed" a lot of forums. So, the activity on typical forums right now is very limited.
I think there are good reasons, why forum-like discussions for certain areas are not too common nowadays. Forums (IMHO) tend to lose a discussion topic, become a place for flamewars and are generally counterproductive. That, in a way, gave rise to SE with stricter QA-rules.
The Julia community has a lot of people who are focused on different aspects of scientific computing. Most of its Discourse Forum is discussions of numerical issues, performance, simulation methods, and scientific computing packages. There's a lot of other associated channels like the JuliaLang slack (here for an invite). The differential equations channel from there is bridged to the DiffEq Gitter with daily discussions on all things differential equations related. There's lot of Slack channels which are highly active like #gpu
, #machine-learning
, #parallel
, #linalg
, etc. where people are discussing algorithms and their implementations. The Julialang/julia Github is very lively as well, though more purpose-driven and requires a bit more prerequisite knowledge to join in. Altogether, it's a great community to discuss with if you're interested in all things scientific computing related.