LogisticRegressionOptimizer opt = new LogisticRegressionOptimizer( logreg, learningRate );
CustomConjugateGradient g = new CustomConjugateGradient(opt);
g.optimize();
Matrix predict = logreg.predict(x);
//log.info(predict.toString());
Evaluation eval = new Evaluation();
eval.eval(y, predict);
//log.info(eval.stats());