ICS 235 Machine Learning Methods Department of Information and Computer Sciences University of Hawai i at M noa Kyungim Baek Announcements Labor day holiday No class on Monday September 2 2 1 Lecture 2 Machine learning concepts A simple example Brief introduction to Python with Jupyter notebook A simple ML example Training data X x1 x2 x3 x4 Y y1 y2 y3 y4 target value x1 2 0 x2 4 0 x3 6 0 x4 8 0 y1 3 0 y2 4 0 y3 5 0 y4 6 0 Prediction problem Given new unknown x what is the value of y Linear model y wx b Parameters w b ML is about finding the optimal parameter values that make the prediction most accurately feature Figure from Oh 2017 3 5 2 A simple ML example Objective function or cost function or loss function To optimize the parameters an objective target value function needs to be defined E g MSE Mean Squared Error cid 3404 1 cid 3533 cid 3036 cid 3398 cid 3036 cid 2870 cid 3041 Goal Find cid 3553 such that cid 3036 cid 2880 cid 2869 cid 3553 cid 3404 argmin feature Figure from Oh 2017 A simple ML example When the training is done the trained model can be used for prediction on new samples E g what is the location y of the moving object after 20 minutes x E g how much rain is expected tomorrow given 90 humidity today Generalization We want the model to perform well on the data it has never seen before rather than the training data 6 7 3 Introduction to Python and Jupyter 8 Jupyter Notebook Uses your browser Combines code with markdown Slide credit P Sadowski 13 4 Jupyter Lab Same as notebooks but with new interface Everything in single browser tab Matter of preference Google Colab https colab research google com Slide credit P Sadowski 14 Slide credit P Sadowski 15 5 Python libraries Machine learning libraries Scikit learn https scikit learn org TensorFlow https tensorflow org Keras https keras io Scientific libraries NumPy https numpy org Matplotlib https matplotlib org Pandas https pandas pydata org SciPy https scipy org Resources Official Python tutorial https docs python org 3 tutorial Learn the syntax LearnPython org https www learnpython org Introduction to Python https scipy lectures org intro language python language html Whirlwind tour of Python with Jupyter Notebooks https github com jakevdp WhirlwindTourOfPython Scikit learn user guide https scikit learn org stable user guide html 16 17 6 Brief introduction to Python with Jupyter notebook Part 1 Basic data types Control flow Functions Classes Part 2 NumPy Matplotlib Pandas Next class Python introduction part 2 cont d NumPy Matplotlib Pandas 18 19 7