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E9 205 Machine Learning for Signal Processing 11-10-2017 Linear Models for Regression and Classification

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Page 1: E9 205 Machine Learning for Signal Processingleap.ee.iisc.ac.in/sriram/teaching/MLSP_17/slides/... · E9 205 Machine Learning for Signal Processing 11-10-2017 Linear Models for Regression

E9 205 Machine Learning for Signal Processing

11-10-2017Linear Models for Regression and

Classification

Page 2: E9 205 Machine Learning for Signal Processingleap.ee.iisc.ac.in/sriram/teaching/MLSP_17/slides/... · E9 205 Machine Learning for Signal Processing 11-10-2017 Linear Models for Regression

Linear Regression

Bishop - PRML book (Chap 3)

❖ Solution to Maximum Likelihood problem is the least squares solution

Pseudo Inverse Based Solution

Page 3: E9 205 Machine Learning for Signal Processingleap.ee.iisc.ac.in/sriram/teaching/MLSP_17/slides/... · E9 205 Machine Learning for Signal Processing 11-10-2017 Linear Models for Regression

Underfit

(Courtesy - Dr D. Vijayasenan, NITK)

Page 4: E9 205 Machine Learning for Signal Processingleap.ee.iisc.ac.in/sriram/teaching/MLSP_17/slides/... · E9 205 Machine Learning for Signal Processing 11-10-2017 Linear Models for Regression

Overfit

(Courtesy - Dr D. Vijayasenan, NITK)

Page 5: E9 205 Machine Learning for Signal Processingleap.ee.iisc.ac.in/sriram/teaching/MLSP_17/slides/... · E9 205 Machine Learning for Signal Processing 11-10-2017 Linear Models for Regression

Compromise

(Courtesy - Dr D. Vijayasenan, NITK)

Page 6: E9 205 Machine Learning for Signal Processingleap.ee.iisc.ac.in/sriram/teaching/MLSP_17/slides/... · E9 205 Machine Learning for Signal Processing 11-10-2017 Linear Models for Regression

Regularized Least Squares

Bishop - PRML book (Chap 3)

❖ Optimize a modified cost function

Page 7: E9 205 Machine Learning for Signal Processingleap.ee.iisc.ac.in/sriram/teaching/MLSP_17/slides/... · E9 205 Machine Learning for Signal Processing 11-10-2017 Linear Models for Regression

Regularized Least Squares

Bishop - PRML book (Chap 3)

Page 8: E9 205 Machine Learning for Signal Processingleap.ee.iisc.ac.in/sriram/teaching/MLSP_17/slides/... · E9 205 Machine Learning for Signal Processing 11-10-2017 Linear Models for Regression

Linear Models for Classification

Bishop - PRML book (Chap 3)

❖ Optimize a modified cost function

Page 9: E9 205 Machine Learning for Signal Processingleap.ee.iisc.ac.in/sriram/teaching/MLSP_17/slides/... · E9 205 Machine Learning for Signal Processing 11-10-2017 Linear Models for Regression

Least Squares for Classification

Bishop - PRML book (Chap 3)

❖ K-class classification problem

❖ With 1-of-K hot encoding, and least squares regression

Page 10: E9 205 Machine Learning for Signal Processingleap.ee.iisc.ac.in/sriram/teaching/MLSP_17/slides/... · E9 205 Machine Learning for Signal Processing 11-10-2017 Linear Models for Regression

Logistic Regression

Bishop - PRML book (Chap 3)

❖ 2- class logistic regression

❖ K-class logistic regression

❖ Maximum likelihood solution

❖ Maximum likelihood solution

Page 11: E9 205 Machine Learning for Signal Processingleap.ee.iisc.ac.in/sriram/teaching/MLSP_17/slides/... · E9 205 Machine Learning for Signal Processing 11-10-2017 Linear Models for Regression

Least Squares versus Logistic Regression

Bishop - PRML book (Chap 4)

Page 12: E9 205 Machine Learning for Signal Processingleap.ee.iisc.ac.in/sriram/teaching/MLSP_17/slides/... · E9 205 Machine Learning for Signal Processing 11-10-2017 Linear Models for Regression

Least Squares versus Logistic Regression

Bishop - PRML book (Chap 4)