Excercises of Coursera online ML course,taught by Andrew Ng #####ex1: Linear Regression #####ex2: Logistic Regression #####ex3: Multi-class Classification and Neural Networks #####ex4: Neural Networks Learning #####ex5: Regularized Linear Regression and Bias v.s. Variance #####ex6: Support Vector Machines #####ex7: K-means Clustering and Principal Component Analysis #####ex7: Anomaly Detection and Recommender Systems