Angrew Machine Learning ex7

estimateGaussian

mu = mean(X)';
sigma2 = mean((X - mu') .^ 2);

selectThreshold

predictions = (pval < epsilon);  
tp = sum(predictions .* yval);
rec = tp / sum(yval);
prec = tp / sum(predictions);
F1 = 2 * rec * prec / (rec + prec);

cofiCostFunc

Y = Y .* R;
P = X * Theta' .* R;
Loss = P - Y;
J = (sum(sum(Loss .^ 2)) + sum(sum(X .^ 2)) * lambda + sum(sum(Theta .^ 2) * lambda))/ 2;
X_grad = Loss * Theta + lambda * X;
Theta_grad = Loss' * X + lambda * Theta;

以上为需要填写的代码部分，完整版代码