Eh? It's not as easy as it sounds. Search for "mlelr" for a rather detailed illustration of how to code LR in C with only standard libraries. Now that was some fun to put together!
(Edit: I'm not saying MOOC-depth derisively. Serious learners and autodidacts can go pretty deep with just MOOCs for guidance. I just mean prima facie, based on content of some of the lighter and more popular MOOCs like Andrew Ng's. Abu-Mostafa's on EdX is meatier.)
Anyone can be quickly taught how to run a logistic regression by calling one line of code from a high level library. But I'd argue it takes years of study to really know what you're doing.