Lecture 14 : Online Learning, Stochastic Gradient Descent, Perceptron
|
|
- Roland Wade
- 6 years ago
- Views:
Transcription
1 CS446: Machine Learning, Fall 2017 Lecture 14 : Online Learning, Stochastic Gradient Descent, Perceptron Lecturer: Sanmi Koyejo Scribe: Ke Wang, Oct. 24th, 2017 Agenda Recap: SVM and Hinge loss, Representer theorem Stochastic Gradient Descent Perceptron, other examples Kernels Recall the feature transformation: For x X, y Y, prediction function is: f : X Y Let φ be the feature transformation function, then we have a mapping: After the transformation, we have: x φ(x) f(x) = w T φ(x) + w 0 Note here f(x) is a linear function with respect to φ(x), and it s a non-linear function with respect to x. (Under the condition that φ(x) is a non-linear function) Define kernel function as: K(x i, x j ) = φ T (x i )φ(x j ) This is especially useful when φ(x) is infinite dimensional. The motivation of infinite dimensional φ(x) is that in theory, you can almost always make your data points linearly 1
2 2 14 : Online Learning, Stochastic Gradient Descent, Perceptron Figure 1: Data lift to higher dimension becomes linear separable, from Kim (2013) spreadable, by bending the data space to infinite dimensional space. See Figure 1 When φ(x) has infinite dimensions, solving w is hard: w T φ(x) where w is also infinite dimensional. Since usually the value of f(x) is in the form of: Φ T (x)φ(x) we can use kernel function to represent f(x), without knowing φ(x) and w For a given data point, We ve shown 2 applications of kernels: f(x) = w T φ(x) f(x) = K(x, x i )α i Linear Regression Using a linear algebra identity SVM Using the method of Lagrange multipliers
3 14 : Online Learning, Stochastic Gradient Descent, Perceptron 3 Hilbert Spaces H k is the space of well behaved linear functions like w T φ(x). And this is equivalent to the space of bounded functions: f(x) = α i K(x, x i ) K(x i, x j ) = φ T (x i )φ(x j ) Support Vector Machines The optimization problem is to maximize the margin, which is proportional to 1 w : s.t where min w y i f(x i ) 1, i [n] f(x) = w T x Why set the threshold to 1? Suppose change that to some constant C: y i f(x i ) C y i f(x i ) C 1 y i w T C x i 1 This won t change the solution to our optimization problem: min w So we can just set C = 1 without losing generality. s.t y i f(x i ) 1, i [n] Non-spreadable Data Recall that with the slack variable ξ i, we have: min w,ξ i w s.t ξ i 0, ξ i yf(x i ) 1 ξ i
4 4 14 : Online Learning, Stochastic Gradient Descent, Perceptron Figure 2: Visualize SVM with slack variable (data points with circle are on the margin) Intuitively, ξ i represents how much tolerance to misclassification the model has. See Figure 2 f(x) = w T φ(x) w = α i y i φ(x i ) where α i 0 w = α i φ(x i, where α i = α i y i When data is separable (no slack), we have α i 0 iff yf(x) = 1 For the non-separable case, we have α i > 0 iff y i f(x i ) = 1 ξ i otherwise α i = 0 The prediction function can be written as this form: f(x) = α i K(x, x i ) i Note that storage for kernel function is O(nd)
5 14 : Online Learning, Stochastic Gradient Descent, Perceptron 5 Whereas storage for SVM is O(dS) Where S is the number of support vectors This is because we can ignore those entries in K with value of K(x, x i ), where x i is not a support vector. Representer Theorem The optimization problem in the Hilbert space is: min f H k Where l(y i, f(x i ) is the loss function. l(y i, f(x i )) + λ f 2 H k Representer Theorem says the solution of this can be written as: f (x) = α i K(x, x i ) We have shown that In kernel ridge regression, use matrix identity we have: l(y i, f(x i ) = (y i f(x i )) 2 In kernel SVM, use dual representation (Lagrange Multipliers) we have: l(y i, f(x i ) = max(0, 1 y i f(x i )) This also applies to other kernel algorithms, for example Kernel logistic regression Kernel Poisson regression
6 6 14 : Online Learning, Stochastic Gradient Descent, Perceptron Stochastic Gradient Descent All the loss functions we ve seen so far is average loss over data points: L(w) = 1 L i (w) n In regression we have: L i (w) = (y i w T x i w 0 ) 2 In SVM we have: L i (w) = max(0, 1 y i (w T x i + w 0 )) The gradient is defined as: w L(w) = 1 n w L i (w) The population empirical risk is: L(w) = E P [L(w)] Under weak conditions we have: L(w) = E P [ w L(w)] We can replace E P [ w L(w)] using a unbiased value, meaning we can pick a β such that: For example, we can choose mean (µ) Let X P, µ = E[X] bias = E[β] E P [ w L(w)] = 0 E[µ] = E [ 1 n ] x i = E[X] We can also choose a single example x i from the data points, because E[x i ] = E[X] So we can choose w L i (w) as an unbiased estimator of E[ w L(w)] Then our Stochastic Gradient Descent algorithm is defined as: In the tth iteration:
7 14 : Online Learning, Stochastic Gradient Descent, Perceptron 7 Pick i uniformly from [n] Update parameter w t+1 = w t + η t w L i (w) go to next iteration until hit stop condition. For example we can limit the number of iterations That is, in each iteration we randomly pick a data point (y i, x i ), and use that data point to calculate L i (w) and L i (w). Then use this randomly selected gradient to update w. For example in the linear regression case: L i (w) = (y i w T x i ) 2 L i (w) = 2x i (y i w T x i ) w t+1 = w t + η t ( 2x i (y i w T x i )) Some useful properties of Stochastic Gradient Descent: Will converge eventually, if L(w) is convex and appropriately choose step size. See Figure 3 and Figure 4 Easily deal with streaming data for online learning. Adaptive. See Figure 5 Deal with non-differentiable functions easily. See Figure 6 Figure 3: Behavior of gradient descent, from Wikipedia, the free encyclopedia (2007). The intuition is: SGD GD + noise w L i (w) w L(w) + noise
8 8 14 : Online Learning, Stochastic Gradient Descent, Perceptron Figure 4: Behavior of stochastic gradient descent Figure 5: SGD model shifts while get new data (new data are the bigger ones) Perceptron Perceptron is an algorithm used for linear classification. If data is separable, perceptron will find a linear separator.
9 14 : Online Learning, Stochastic Gradient Descent, Perceptron 9 Figure 6: GD gets stuck at the flat point, but SGD won t Consider the linear model where f(x) = w T x + w 0 h(x) = sign ( f(x) ) The loss function is: L i (w) = max ( 0, yf(x) ) Then we have the gradient: 0, y i f(x i ) > 0 w L i (w) = y i x i, y i f(x i ) < 0 0, y i f(x i ) = 0 The perceptron algorithm is defined as: For i [n], the update rule in each iteration is: w t+1 = w t, { wt + η t y i x i, if y i f(x i ) < 0 (wrong prediction) if y i f(x i ) > 0 (correct prediction)
10 10 14 : Online Learning, Stochastic Gradient Descent, Perceptron
11 Bibliography Kim, E. (2013). (left) the decision boundary w shown to be linear in 3-d space, (right) the decision boundary w, when transformed back to 2-d space, is nonlinear. [Online; accessed October 24, 2017]. URL Wikipedia, the free encyclopedia (2007). Illustration of gradient descent on a series of level sets. [Online; accessed October 24, 2017]. URL 11
Machine Learning. Support Vector Machines. Fabio Vandin November 20, 2017
Machine Learning Support Vector Machines Fabio Vandin November 20, 2017 1 Classification and Margin Consider a classification problem with two classes: instance set X = R d label set Y = { 1, 1}. Training
More informationTopics we covered. Machine Learning. Statistics. Optimization. Systems! Basics of probability Tail bounds Density Estimation Exponential Families
Midterm Review Topics we covered Machine Learning Optimization Basics of optimization Convexity Unconstrained: GD, SGD Constrained: Lagrange, KKT Duality Linear Methods Perceptrons Support Vector Machines
More informationIntroduction to Logistic Regression and Support Vector Machine
Introduction to Logistic Regression and Support Vector Machine guest lecturer: Ming-Wei Chang CS 446 Fall, 2009 () / 25 Fall, 2009 / 25 Before we start () 2 / 25 Fall, 2009 2 / 25 Before we start Feel
More informationMax Margin-Classifier
Max Margin-Classifier Oliver Schulte - CMPT 726 Bishop PRML Ch. 7 Outline Maximum Margin Criterion Math Maximizing the Margin Non-Separable Data Kernels and Non-linear Mappings Where does the maximization
More informationSupport Vector Machines, Kernel SVM
Support Vector Machines, Kernel SVM Professor Ameet Talwalkar Professor Ameet Talwalkar CS260 Machine Learning Algorithms February 27, 2017 1 / 40 Outline 1 Administration 2 Review of last lecture 3 SVM
More informationLecture 9: Large Margin Classifiers. Linear Support Vector Machines
Lecture 9: Large Margin Classifiers. Linear Support Vector Machines Perceptrons Definition Perceptron learning rule Convergence Margin & max margin classifiers (Linear) support vector machines Formulation
More informationDeep Learning for Computer Vision
Deep Learning for Computer Vision Lecture 4: Curse of Dimensionality, High Dimensional Feature Spaces, Linear Classifiers, Linear Regression, Python, and Jupyter Notebooks Peter Belhumeur Computer Science
More informationCheng Soon Ong & Christian Walder. Canberra February June 2018
Cheng Soon Ong & Christian Walder Research Group and College of Engineering and Computer Science Canberra February June 2018 Outlines Overview Introduction Linear Algebra Probability Linear Regression
More informationMark your answers ON THE EXAM ITSELF. If you are not sure of your answer you may wish to provide a brief explanation.
CS 189 Spring 2015 Introduction to Machine Learning Midterm You have 80 minutes for the exam. The exam is closed book, closed notes except your one-page crib sheet. No calculators or electronic items.
More informationECS171: Machine Learning
ECS171: Machine Learning Lecture 4: Optimization (LFD 3.3, SGD) Cho-Jui Hsieh UC Davis Jan 22, 2018 Gradient descent Optimization Goal: find the minimizer of a function min f (w) w For now we assume f
More informationMachine Learning Support Vector Machines. Prof. Matteo Matteucci
Machine Learning Support Vector Machines Prof. Matteo Matteucci Discriminative vs. Generative Approaches 2 o Generative approach: we derived the classifier from some generative hypothesis about the way
More informationDiscriminative Models
No.5 Discriminative Models Hui Jiang Department of Electrical Engineering and Computer Science Lassonde School of Engineering York University, Toronto, Canada Outline Generative vs. Discriminative models
More informationLinear Regression (continued)
Linear Regression (continued) Professor Ameet Talwalkar Professor Ameet Talwalkar CS260 Machine Learning Algorithms February 6, 2017 1 / 39 Outline 1 Administration 2 Review of last lecture 3 Linear regression
More informationStat542 (F11) Statistical Learning. First consider the scenario where the two classes of points are separable.
Linear SVM (separable case) First consider the scenario where the two classes of points are separable. It s desirable to have the width (called margin) between the two dashed lines to be large, i.e., have
More informationOptimization and Gradient Descent
Optimization and Gradient Descent INFO-4604, Applied Machine Learning University of Colorado Boulder September 12, 2017 Prof. Michael Paul Prediction Functions Remember: a prediction function is the function
More informationMachine Learning Basics Lecture 4: SVM I. Princeton University COS 495 Instructor: Yingyu Liang
Machine Learning Basics Lecture 4: SVM I Princeton University COS 495 Instructor: Yingyu Liang Review: machine learning basics Math formulation Given training data x i, y i : 1 i n i.i.d. from distribution
More informationSupport Vector Machine (continued)
Support Vector Machine continued) Overlapping class distribution: In practice the class-conditional distributions may overlap, so that the training data points are no longer linearly separable. We need
More informationHOMEWORK 4: SVMS AND KERNELS
HOMEWORK 4: SVMS AND KERNELS CMU 060: MACHINE LEARNING (FALL 206) OUT: Sep. 26, 206 DUE: 5:30 pm, Oct. 05, 206 TAs: Simon Shaolei Du, Tianshu Ren, Hsiao-Yu Fish Tung Instructions Homework Submission: Submit
More informationICS-E4030 Kernel Methods in Machine Learning
ICS-E4030 Kernel Methods in Machine Learning Lecture 3: Convex optimization and duality Juho Rousu 28. September, 2016 Juho Rousu 28. September, 2016 1 / 38 Convex optimization Convex optimisation This
More informationLinear & nonlinear classifiers
Linear & nonlinear classifiers Machine Learning Hamid Beigy Sharif University of Technology Fall 1394 Hamid Beigy (Sharif University of Technology) Linear & nonlinear classifiers Fall 1394 1 / 34 Table
More informationOverfitting, Bias / Variance Analysis
Overfitting, Bias / Variance Analysis Professor Ameet Talwalkar Professor Ameet Talwalkar CS260 Machine Learning Algorithms February 8, 207 / 40 Outline Administration 2 Review of last lecture 3 Basic
More informationDiscriminative Models
No.5 Discriminative Models Hui Jiang Department of Electrical Engineering and Computer Science Lassonde School of Engineering York University, Toronto, Canada Outline Generative vs. Discriminative models
More informationSVMs, Duality and the Kernel Trick
SVMs, Duality and the Kernel Trick Machine Learning 10701/15781 Carlos Guestrin Carnegie Mellon University February 26 th, 2007 2005-2007 Carlos Guestrin 1 SVMs reminder 2005-2007 Carlos Guestrin 2 Today
More informationChapter 9. Support Vector Machine. Yongdai Kim Seoul National University
Chapter 9. Support Vector Machine Yongdai Kim Seoul National University 1. Introduction Support Vector Machine (SVM) is a classification method developed by Vapnik (1996). It is thought that SVM improved
More informationSupport Vector Machines
EE 17/7AT: Optimization Models in Engineering Section 11/1 - April 014 Support Vector Machines Lecturer: Arturo Fernandez Scribe: Arturo Fernandez 1 Support Vector Machines Revisited 1.1 Strictly) Separable
More informationSupport Vector Machines: Training with Stochastic Gradient Descent. Machine Learning Fall 2017
Support Vector Machines: Training with Stochastic Gradient Descent Machine Learning Fall 2017 1 Support vector machines Training by maximizing margin The SVM objective Solving the SVM optimization problem
More informationSTA141C: Big Data & High Performance Statistical Computing
STA141C: Big Data & High Performance Statistical Computing Lecture 8: Optimization Cho-Jui Hsieh UC Davis May 9, 2017 Optimization Numerical Optimization Numerical Optimization: min X f (X ) Can be applied
More informationSupport Vector Machines. Introduction to Data Mining, 2 nd Edition by Tan, Steinbach, Karpatne, Kumar
Data Mining Support Vector Machines Introduction to Data Mining, 2 nd Edition by Tan, Steinbach, Karpatne, Kumar 02/03/2018 Introduction to Data Mining 1 Support Vector Machines Find a linear hyperplane
More informationContents. 1 Introduction. 1.1 History of Optimization ALG-ML SEMINAR LISSA: LINEAR TIME SECOND-ORDER STOCHASTIC ALGORITHM FEBRUARY 23, 2016
ALG-ML SEMINAR LISSA: LINEAR TIME SECOND-ORDER STOCHASTIC ALGORITHM FEBRUARY 23, 2016 LECTURERS: NAMAN AGARWAL AND BRIAN BULLINS SCRIBE: KIRAN VODRAHALLI Contents 1 Introduction 1 1.1 History of Optimization.....................................
More informationSupport Vector Machines and Kernel Methods
2018 CS420 Machine Learning, Lecture 3 Hangout from Prof. Andrew Ng. http://cs229.stanford.edu/notes/cs229-notes3.pdf Support Vector Machines and Kernel Methods Weinan Zhang Shanghai Jiao Tong University
More informationIndirect Rule Learning: Support Vector Machines. Donglin Zeng, Department of Biostatistics, University of North Carolina
Indirect Rule Learning: Support Vector Machines Indirect learning: loss optimization It doesn t estimate the prediction rule f (x) directly, since most loss functions do not have explicit optimizers. Indirection
More informationMidterm. Introduction to Machine Learning. CS 189 Spring You have 1 hour 20 minutes for the exam.
CS 189 Spring 2013 Introduction to Machine Learning Midterm You have 1 hour 20 minutes for the exam. The exam is closed book, closed notes except your one-page crib sheet. Please use non-programmable calculators
More informationSupport Vector Machines
Support Vector Machines INFO-4604, Applied Machine Learning University of Colorado Boulder September 28, 2017 Prof. Michael Paul Today Two important concepts: Margins Kernels Large Margin Classification
More informationSupport vector machines Lecture 4
Support vector machines Lecture 4 David Sontag New York University Slides adapted from Luke Zettlemoyer, Vibhav Gogate, and Carlos Guestrin Q: What does the Perceptron mistake bound tell us? Theorem: The
More informationStatistical Pattern Recognition
Statistical Pattern Recognition Support Vector Machine (SVM) Hamid R. Rabiee Hadi Asheri, Jafar Muhammadi, Nima Pourdamghani Spring 2013 http://ce.sharif.edu/courses/91-92/2/ce725-1/ Agenda Introduction
More informationCSC 411 Lecture 17: Support Vector Machine
CSC 411 Lecture 17: Support Vector Machine Ethan Fetaya, James Lucas and Emad Andrews University of Toronto CSC411 Lec17 1 / 1 Today Max-margin classification SVM Hard SVM Duality Soft SVM CSC411 Lec17
More informationSupport Vector Machines
Support Vector Machines Support vector machines (SVMs) are one of the central concepts in all of machine learning. They are simply a combination of two ideas: linear classification via maximum (or optimal
More informationCS260: Machine Learning Algorithms
CS260: Machine Learning Algorithms Lecture 4: Stochastic Gradient Descent Cho-Jui Hsieh UCLA Jan 16, 2019 Large-scale Problems Machine learning: usually minimizing the training loss min w { 1 N min w {
More information18.9 SUPPORT VECTOR MACHINES
744 Chapter 8. Learning from Examples is the fact that each regression problem will be easier to solve, because it involves only the examples with nonzero weight the examples whose kernels overlap the
More informationCS-E4830 Kernel Methods in Machine Learning
CS-E4830 Kernel Methods in Machine Learning Lecture 3: Convex optimization and duality Juho Rousu 27. September, 2017 Juho Rousu 27. September, 2017 1 / 45 Convex optimization Convex optimisation This
More informationMachine Learning A Geometric Approach
Machine Learning A Geometric Approach CIML book Chap 7.7 Linear Classification: Support Vector Machines (SVM) Professor Liang Huang some slides from Alex Smola (CMU) Linear Separator Ham Spam From Perceptron
More informationSupport Vector Machine (SVM) & Kernel CE-717: Machine Learning Sharif University of Technology. M. Soleymani Fall 2012
Support Vector Machine (SVM) & Kernel CE-717: Machine Learning Sharif University of Technology M. Soleymani Fall 2012 Linear classifier Which classifier? x 2 x 1 2 Linear classifier Margin concept x 2
More informationMLCC 2017 Regularization Networks I: Linear Models
MLCC 2017 Regularization Networks I: Linear Models Lorenzo Rosasco UNIGE-MIT-IIT June 27, 2017 About this class We introduce a class of learning algorithms based on Tikhonov regularization We study computational
More informationCS145: INTRODUCTION TO DATA MINING
CS145: INTRODUCTION TO DATA MINING 5: Vector Data: Support Vector Machine Instructor: Yizhou Sun yzsun@cs.ucla.edu October 18, 2017 Homework 1 Announcements Due end of the day of this Thursday (11:59pm)
More informationSupport Vector Machines for Classification: A Statistical Portrait
Support Vector Machines for Classification: A Statistical Portrait Yoonkyung Lee Department of Statistics The Ohio State University May 27, 2011 The Spring Conference of Korean Statistical Society KAIST,
More informationLinear Models in Machine Learning
CS540 Intro to AI Linear Models in Machine Learning Lecturer: Xiaojin Zhu jerryzhu@cs.wisc.edu We briefly go over two linear models frequently used in machine learning: linear regression for, well, regression,
More informationAnnouncements - Homework
Announcements - Homework Homework 1 is graded, please collect at end of lecture Homework 2 due today Homework 3 out soon (watch email) Ques 1 midterm review HW1 score distribution 40 HW1 total score 35
More informationKernelized Perceptron Support Vector Machines
Kernelized Perceptron Support Vector Machines Emily Fox University of Washington February 13, 2017 What is the perceptron optimizing? 1 The perceptron algorithm [Rosenblatt 58, 62] Classification setting:
More informationWarm up: risk prediction with logistic regression
Warm up: risk prediction with logistic regression Boss gives you a bunch of data on loans defaulting or not: {(x i,y i )} n i= x i 2 R d, y i 2 {, } You model the data as: P (Y = y x, w) = + exp( yw T
More informationSupport Vector Machines. CSE 6363 Machine Learning Vassilis Athitsos Computer Science and Engineering Department University of Texas at Arlington
Support Vector Machines CSE 6363 Machine Learning Vassilis Athitsos Computer Science and Engineering Department University of Texas at Arlington 1 A Linearly Separable Problem Consider the binary classification
More informationDan Roth 461C, 3401 Walnut
CIS 519/419 Applied Machine Learning www.seas.upenn.edu/~cis519 Dan Roth danroth@seas.upenn.edu http://www.cis.upenn.edu/~danroth/ 461C, 3401 Walnut Slides were created by Dan Roth (for CIS519/419 at Penn
More informationLecture Support Vector Machine (SVM) Classifiers
Introduction to Machine Learning Lecturer: Amir Globerson Lecture 6 Fall Semester Scribe: Yishay Mansour 6.1 Support Vector Machine (SVM) Classifiers Classification is one of the most important tasks in
More informationLinear classifiers: Overfitting and regularization
Linear classifiers: Overfitting and regularization Emily Fox University of Washington January 25, 2017 Logistic regression recap 1 . Thus far, we focused on decision boundaries Score(x i ) = w 0 h 0 (x
More informationKernel Methods and Support Vector Machines
Kernel Methods and Support Vector Machines Oliver Schulte - CMPT 726 Bishop PRML Ch. 6 Support Vector Machines Defining Characteristics Like logistic regression, good for continuous input features, discrete
More informationNon-Bayesian Classifiers Part II: Linear Discriminants and Support Vector Machines
Non-Bayesian Classifiers Part II: Linear Discriminants and Support Vector Machines Selim Aksoy Department of Computer Engineering Bilkent University saksoy@cs.bilkent.edu.tr CS 551, Fall 2018 CS 551, Fall
More informationECS289: Scalable Machine Learning
ECS289: Scalable Machine Learning Cho-Jui Hsieh UC Davis Sept 29, 2016 Outline Convex vs Nonconvex Functions Coordinate Descent Gradient Descent Newton s method Stochastic Gradient Descent Numerical Optimization
More informationMachine Learning & Data Mining CS/CNS/EE 155. Lecture 4: Regularization, Sparsity & Lasso
Machine Learning Data Mining CS/CS/EE 155 Lecture 4: Regularization, Sparsity Lasso 1 Recap: Complete Pipeline S = {(x i, y i )} Training Data f (x, b) = T x b Model Class(es) L(a, b) = (a b) 2 Loss Function,b
More informationL5 Support Vector Classification
L5 Support Vector Classification Support Vector Machine Problem definition Geometrical picture Optimization problem Optimization Problem Hard margin Convexity Dual problem Soft margin problem Alexander
More informationCSE 417T: Introduction to Machine Learning. Lecture 11: Review. Henry Chai 10/02/18
CSE 417T: Introduction to Machine Learning Lecture 11: Review Henry Chai 10/02/18 Unknown Target Function!: # % Training data Formal Setup & = ( ), + ),, ( -, + - Learning Algorithm 2 Hypothesis Set H
More informationMachine Learning And Applications: Supervised Learning-SVM
Machine Learning And Applications: Supervised Learning-SVM Raphaël Bournhonesque École Normale Supérieure de Lyon, Lyon, France raphael.bournhonesque@ens-lyon.fr 1 Supervised vs unsupervised learning Machine
More informationCS6375: Machine Learning Gautam Kunapuli. Support Vector Machines
Gautam Kunapuli Example: Text Categorization Example: Develop a model to classify news stories into various categories based on their content. sports politics Use the bag-of-words representation for this
More informationLinear & nonlinear classifiers
Linear & nonlinear classifiers Machine Learning Hamid Beigy Sharif University of Technology Fall 1396 Hamid Beigy (Sharif University of Technology) Linear & nonlinear classifiers Fall 1396 1 / 44 Table
More informationLinear classifiers selecting hyperplane maximizing separation margin between classes (large margin classifiers)
Support vector machines In a nutshell Linear classifiers selecting hyperplane maximizing separation margin between classes (large margin classifiers) Solution only depends on a small subset of training
More informationComputational and Statistical Learning Theory
Computational and Statistical Learning Theory TTIC 31120 Prof. Nati Srebro Lecture 17: Stochastic Optimization Part II: Realizable vs Agnostic Rates Part III: Nearest Neighbor Classification Stochastic
More informationSupport Vector Machine (SVM) and Kernel Methods
Support Vector Machine (SVM) and Kernel Methods CE-717: Machine Learning Sharif University of Technology Fall 2016 Soleymani Outline Margin concept Hard-Margin SVM Soft-Margin SVM Dual Problems of Hard-Margin
More informationNeural Networks and Deep Learning
Neural Networks and Deep Learning Professor Ameet Talwalkar November 12, 2015 Professor Ameet Talwalkar Neural Networks and Deep Learning November 12, 2015 1 / 16 Outline 1 Review of last lecture AdaBoost
More informationLinear classifiers selecting hyperplane maximizing separation margin between classes (large margin classifiers)
Support vector machines In a nutshell Linear classifiers selecting hyperplane maximizing separation margin between classes (large margin classifiers) Solution only depends on a small subset of training
More informationSupport Vector Machines and Bayes Regression
Statistical Techniques in Robotics (16-831, F11) Lecture #14 (Monday ctober 31th) Support Vector Machines and Bayes Regression Lecturer: Drew Bagnell Scribe: Carl Doersch 1 1 Linear SVMs We begin by considering
More informationCIS 520: Machine Learning Oct 09, Kernel Methods
CIS 520: Machine Learning Oct 09, 207 Kernel Methods Lecturer: Shivani Agarwal Disclaimer: These notes are designed to be a supplement to the lecture They may or may not cover all the material discussed
More informationCOMP 652: Machine Learning. Lecture 12. COMP Lecture 12 1 / 37
COMP 652: Machine Learning Lecture 12 COMP 652 Lecture 12 1 / 37 Today Perceptrons Definition Perceptron learning rule Convergence (Linear) support vector machines Margin & max margin classifier Formulation
More informationKernel Machines. Pradeep Ravikumar Co-instructor: Manuela Veloso. Machine Learning
Kernel Machines Pradeep Ravikumar Co-instructor: Manuela Veloso Machine Learning 10-701 SVM linearly separable case n training points (x 1,, x n ) d features x j is a d-dimensional vector Primal problem:
More informationSVMs: Non-Separable Data, Convex Surrogate Loss, Multi-Class Classification, Kernels
SVMs: Non-Separable Data, Convex Surrogate Loss, Multi-Class Classification, Kernels Karl Stratos June 21, 2018 1 / 33 Tangent: Some Loose Ends in Logistic Regression Polynomial feature expansion in logistic
More informationMachine Learning. Support Vector Machines. Manfred Huber
Machine Learning Support Vector Machines Manfred Huber 2015 1 Support Vector Machines Both logistic regression and linear discriminant analysis learn a linear discriminant function to separate the data
More informationOslo Class 2 Tikhonov regularization and kernels
RegML2017@SIMULA Oslo Class 2 Tikhonov regularization and kernels Lorenzo Rosasco UNIGE-MIT-IIT May 3, 2017 Learning problem Problem For H {f f : X Y }, solve min E(f), f H dρ(x, y)l(f(x), y) given S n
More informationSupport Vector Machines
Support Vector Machines Some material on these is slides borrowed from Andrew Moore's excellent machine learning tutorials located at: http://www.cs.cmu.edu/~awm/tutorials/ Where Should We Draw the Line????
More informationMachine Learning Practice Page 2 of 2 10/28/13
Machine Learning 10-701 Practice Page 2 of 2 10/28/13 1. True or False Please give an explanation for your answer, this is worth 1 pt/question. (a) (2 points) No classifier can do better than a naive Bayes
More informationSupport Vector Machines
Two SVM tutorials linked in class website (please, read both): High-level presentation with applications (Hearst 1998) Detailed tutorial (Burges 1998) Support Vector Machines Machine Learning 10701/15781
More informationClassification Logistic Regression
Announcements: Classification Logistic Regression Machine Learning CSE546 Sham Kakade University of Washington HW due on Friday. Today: Review: sub-gradients,lasso Logistic Regression October 3, 26 Sham
More informationLINEAR CLASSIFICATION, PERCEPTRON, LOGISTIC REGRESSION, SVC, NAÏVE BAYES. Supervised Learning
LINEAR CLASSIFICATION, PERCEPTRON, LOGISTIC REGRESSION, SVC, NAÏVE BAYES Supervised Learning Linear vs non linear classifiers In K-NN we saw an example of a non-linear classifier: the decision boundary
More informationRegML 2018 Class 2 Tikhonov regularization and kernels
RegML 2018 Class 2 Tikhonov regularization and kernels Lorenzo Rosasco UNIGE-MIT-IIT June 17, 2018 Learning problem Problem For H {f f : X Y }, solve min E(f), f H dρ(x, y)l(f(x), y) given S n = (x i,
More informationOnline Learning With Kernel
CS 446 Machine Learning Fall 2016 SEP 27, 2016 Online Learning With Kernel Professor: Dan Roth Scribe: Ben Zhou, C. Cervantes Overview Stochastic Gradient Descent Algorithms Regularization Algorithm Issues
More informationMachine Learning for NLP
Machine Learning for NLP Linear Models Joakim Nivre Uppsala University Department of Linguistics and Philology Slides adapted from Ryan McDonald, Google Research Machine Learning for NLP 1(26) Outline
More informationStochastic Gradient Descent. CS 584: Big Data Analytics
Stochastic Gradient Descent CS 584: Big Data Analytics Gradient Descent Recap Simplest and extremely popular Main Idea: take a step proportional to the negative of the gradient Easy to implement Each iteration
More informationMidterm exam CS 189/289, Fall 2015
Midterm exam CS 189/289, Fall 2015 You have 80 minutes for the exam. Total 100 points: 1. True/False: 36 points (18 questions, 2 points each). 2. Multiple-choice questions: 24 points (8 questions, 3 points
More informationSupport Vector Machines for Classification and Regression. 1 Linearly Separable Data: Hard Margin SVMs
E0 270 Machine Learning Lecture 5 (Jan 22, 203) Support Vector Machines for Classification and Regression Lecturer: Shivani Agarwal Disclaimer: These notes are a brief summary of the topics covered in
More information(Kernels +) Support Vector Machines
(Kernels +) Support Vector Machines Machine Learning Torsten Möller Reading Chapter 5 of Machine Learning An Algorithmic Perspective by Marsland Chapter 6+7 of Pattern Recognition and Machine Learning
More informationBits of Machine Learning Part 1: Supervised Learning
Bits of Machine Learning Part 1: Supervised Learning Alexandre Proutiere and Vahan Petrosyan KTH (The Royal Institute of Technology) Outline of the Course 1. Supervised Learning Regression and Classification
More informationCSCI567 Machine Learning (Fall 2014)
CSCI567 Machine Learning (Fall 24) Drs. Sha & Liu {feisha,yanliu.cs}@usc.edu October 2, 24 Drs. Sha & Liu ({feisha,yanliu.cs}@usc.edu) CSCI567 Machine Learning (Fall 24) October 2, 24 / 24 Outline Review
More informationSupport Vector Machines for Classification and Regression
CIS 520: Machine Learning Oct 04, 207 Support Vector Machines for Classification and Regression Lecturer: Shivani Agarwal Disclaimer: These notes are designed to be a supplement to the lecture. They may
More informationMachine Learning Lecture 6 Note
Machine Learning Lecture 6 Note Compiled by Abhi Ashutosh, Daniel Chen, and Yijun Xiao February 16, 2016 1 Pegasos Algorithm The Pegasos Algorithm looks very similar to the Perceptron Algorithm. In fact,
More informationSupport Vector Machines
Wien, June, 2010 Paul Hofmarcher, Stefan Theussl, WU Wien Hofmarcher/Theussl SVM 1/21 Linear Separable Separating Hyperplanes Non-Linear Separable Soft-Margin Hyperplanes Hofmarcher/Theussl SVM 2/21 (SVM)
More informationIFT Lecture 6 Nesterov s Accelerated Gradient, Stochastic Gradient Descent
IFT 6085 - Lecture 6 Nesterov s Accelerated Gradient, Stochastic Gradient Descent This version of the notes has not yet been thoroughly checked. Please report any bugs to the scribes or instructor. Scribe(s):
More informationStatistical Methods for Data Mining
Statistical Methods for Data Mining Kuangnan Fang Xiamen University Email: xmufkn@xmu.edu.cn Support Vector Machines Here we approach the two-class classification problem in a direct way: We try and find
More informationSupport Vector Machines
Support Vector Machines Hypothesis Space variable size deterministic continuous parameters Learning Algorithm linear and quadratic programming eager batch SVMs combine three important ideas Apply optimization
More informationHomework 2 Solutions Kernel SVM and Perceptron
Homework 2 Solutions Kernel SVM and Perceptron CMU 1-71: Machine Learning (Fall 21) https://piazza.com/cmu/fall21/17115781/home OUT: Sept 25, 21 DUE: Oct 8, 11:59 PM Problem 1: SVM decision boundaries
More informationMachine Learning and Data Mining. Linear classification. Kalev Kask
Machine Learning and Data Mining Linear classification Kalev Kask Supervised learning Notation Features x Targets y Predictions ŷ = f(x ; q) Parameters q Program ( Learner ) Learning algorithm Change q
More informationIntroduction to Support Vector Machines
Introduction to Support Vector Machines Shivani Agarwal Support Vector Machines (SVMs) Algorithm for learning linear classifiers Motivated by idea of maximizing margin Efficient extension to non-linear
More informationLecture 18: Kernels Risk and Loss Support Vector Regression. Aykut Erdem December 2016 Hacettepe University
Lecture 18: Kernels Risk and Loss Support Vector Regression Aykut Erdem December 2016 Hacettepe University Administrative We will have a make-up lecture on next Saturday December 24, 2016 Presentations
More informationLearning From Data Lecture 9 Logistic Regression and Gradient Descent
Learning From Data Lecture 9 Logistic Regression and Gradient Descent Logistic Regression Gradient Descent M. Magdon-Ismail CSCI 4100/6100 recap: Linear Classification and Regression The linear signal:
More informationConvex Optimization Lecture 16
Convex Optimization Lecture 16 Today: Projected Gradient Descent Conditional Gradient Descent Stochastic Gradient Descent Random Coordinate Descent Recall: Gradient Descent (Steepest Descent w.r.t Euclidean
More information