optim
A numeric optimization package for Torch.
A collection of optimization algorithms (like SGD) for training machine learning models in Torch, a numerical computing framework written in Lua.
What this package does
This is a collection of optimization algorithms for machine learning models built in Torch, a numerical computing framework. Think of it as a toolkit that helps you train neural networks and other models by automatically adjusting their parameters to get better results. When you're training a model, you need a systematic way to tweak thousands (or millions) of numbers to minimize errors—that's what this package does.
How it works
The package provides several different optimization methods, each with the same basic workflow. You give it three things: a function that calculates how wrong your model is (and how to fix it), your current model parameters, and some settings like learning rate. The algorithm then figures out better parameters to use next. The function returns the improved parameters and keeps a record of all the error values along the way, so you can track whether your model is actually getting better.
The clever part is that the "state" (the settings and internal memory of each algorithm) is kept in a simple table that you control. You set it up once with whatever configuration makes sense for your problem—like how aggressively to adjust the parameters—and then pass it along each time you want to improve your model. This lets the algorithm remember where it left off and build on previous progress.
Who would use this
Machine learning researchers and engineers working in Lua or Torch would use this to train their models. If you're building a neural network for image recognition, natural language processing, or any other task, you'd pick one of these optimization methods (the README mentions SGD as an example) and use it repeatedly to teach your model. It's the kind of foundational tool that's invisible to end users but essential for anyone building the models themselves.
Where it fits
- Train a neural network by repeatedly calling an optimizer to adjust its parameters.
- Track training progress by recording error values returned on each update step.
- Swap in different optimization methods like SGD without changing your training loop.
- Persist optimizer state between runs so training can resume where it left off.