Deep Learning: Theory and Practice - LEAP Laboratory...Deep Learning: Theory and Practice 14-02-2019...

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Deep Learning: Theory and Practice 14-02-2019 Linear and Logistic Models for Classification [email protected]

Transcript of Deep Learning: Theory and Practice - LEAP Laboratory...Deep Learning: Theory and Practice 14-02-2019...

Page 1: Deep Learning: Theory and Practice - LEAP Laboratory...Deep Learning: Theory and Practice 14-02-2019 Linear and Logistic Models for Classification deeplearning.cce2019@gmail.com Logistic

Deep Learning: Theory and Practice

14-02-2019Linear and Logistic Models for

Classification

[email protected]

Page 2: Deep Learning: Theory and Practice - LEAP Laboratory...Deep Learning: Theory and Practice 14-02-2019 Linear and Logistic Models for Classification deeplearning.cce2019@gmail.com Logistic

Logistic Regression

Bishop - PRML book (Chap 3)

❖ 2- class logistic regression

❖ K-class logistic regression

❖ Maximum likelihood solution

❖ Maximum likelihood solution

Page 3: Deep Learning: Theory and Practice - LEAP Laboratory...Deep Learning: Theory and Practice 14-02-2019 Linear and Logistic Models for Classification deeplearning.cce2019@gmail.com Logistic

Least Squares versus Logistic Regression

Bishop - PRML book (Chap 4)

Page 4: Deep Learning: Theory and Practice - LEAP Laboratory...Deep Learning: Theory and Practice 14-02-2019 Linear and Logistic Models for Classification deeplearning.cce2019@gmail.com Logistic

Least Squares versus Logistic Regression

Bishop - PRML book (Chap 4)

Page 5: Deep Learning: Theory and Practice - LEAP Laboratory...Deep Learning: Theory and Practice 14-02-2019 Linear and Logistic Models for Classification deeplearning.cce2019@gmail.com Logistic

Underfit

(Courtesy - Dr D. Vijayasenan, NITK)

Page 6: Deep Learning: Theory and Practice - LEAP Laboratory...Deep Learning: Theory and Practice 14-02-2019 Linear and Logistic Models for Classification deeplearning.cce2019@gmail.com Logistic

Overfit

(Courtesy - Dr D. Vijayasenan, NITK)

Page 7: Deep Learning: Theory and Practice - LEAP Laboratory...Deep Learning: Theory and Practice 14-02-2019 Linear and Logistic Models for Classification deeplearning.cce2019@gmail.com Logistic

Compromise

(Courtesy - Dr D. Vijayasenan, NITK)

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Summary so far …

Bishop - PRML book (Chap 3)

❖ Maximum Likelihood

❖ Linear Least Squares Classifiers

❖ Logistic Regression

❖ Application of ML to Logistic Regression

❖ Gradient Descent

❖ Coding Logistic regression

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Training, Validation and Test Set

Page 10: Deep Learning: Theory and Practice - LEAP Laboratory...Deep Learning: Theory and Practice 14-02-2019 Linear and Logistic Models for Classification deeplearning.cce2019@gmail.com Logistic

Perceptron Algorithm

What if the data is not linearly separable

Perceptron Model [McCulloch, 1943, Rosenblatt, 1957]

Targets are binary classes [-1,1]

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Multi-layer PerceptronMulti-layer Perceptron [Hopfield, 1982]

thresholding function

non-linear function (tanh,sigmoid)