Writing out a keyified version of the training data
Brain dead initial version of logistic regression for Facebook 2 Kaggle competition
Jumped from position 110 to position 52.  Still not beating the benchmark at position 36, but doing better than random guessing :-)
Moved from position 52 to position 49.  Made a few performance optimizations by reusing DataInstance and other objects.  Removed bias from the model by nuking the intercept and cost features from the existence model.
Added loss computation to model.  Checking in prior to refactoring for reuse.
Splitting code into what is reusable across models and what is not.
Not getting great results yet, but the code is factored nicely now.
starter code for homework 4