Rails: where to put statistics code?

I have a Rails app that uses a lot of custom st开发者_C百科atistics code I wrote, things like calculating the mean and standard deviation of an array of numbers, or calculating statistical significance tests.

Where do I put all this code? It's not tied to any database object, so I'm guessing it shouldn't go into /models. And if I understand correctly, /app/helpers is only for helper functions called from your views, so I don't think it should go there. Am I supposed to put my statistics code into /lib?

In general, I'm not sure where I'm supposed to put helper libraries that are called from my models.

As an aside, you can definitely have models that aren't tied to database tables, but they should still be classes that represent "things" in your domain, in my opinion. So I still wouldn't put them in /models, but not because of anything to do with the database.

I would put them in /lib, yes. Note that they won't be loaded by Rails automatically, so you'll want to add require statements in an initializer.

If this code is only useful for this project, then /lib is a good place. However, you might also consider packaging it into a gem if you think you might use the code in another project later on, especially if you're going to have more than one project using this code at the same time.

/lib sounds good for these stuffs

Agreed, putting your code into a module that can be included into your models is the way to go. That usually goes into lib/