Probability Intro Part II: Bayes Rule

Size: px
Start display at page:

Download "Probability Intro Part II: Bayes Rule"

Transcription

1 Probability Intro Part II: Bayes Rule Jonathan Pillow Mathematical Tools for Neuroscience (NEU 314) Spring, 2016 lecture 13

2 Quick recap Random variable X takes on different values according to a probability distribution discrete: probability mass function (pmf) continuous: probability density function (pdf) marginalization: summing ( splatting ) conditionalization: slicing

3 conditionalization ( slicing ) 3 2 ( joint divided by marginal )

4 conditionalization ( slicing ) 3 2 ( joint divided by marginal )

5 conditionalization ( slicing ) conditional marginal P(x)

6 conditional densities

7 conditional densities

8 Bayes Rule Conditional Densities likelihood prior Bayes Rule posterior marginal probability of y ( normalizer )

9 A little math: Bayes rule very simple formula for manipulating probabilities P(B A) = conditional probability probability of B given that A occurred P(A B) P(B) P(A) probability of B probability of A simplified form: P(B A) P(A B) P(B)

10 Example: 2 coins A little math: Bayes rule P(B A) P(A B) P(B) one coin is fake: heads on both sides (H / H) one coin is standard: (H / T) You grab one of the coins at random and flip it. It comes up heads. What is the probability that you re holding the fake? p( Fake H) p(h Fake) p(fake) ( 1 ) ( ½ ) = ½ p( Nrml H) p (H Nrml) p(nrml) ( ½ ) ( ½ ) = ¼ probabilities must sum to 1

11 A little math: Bayes rule P(B A) P(A B) P(B) Example: 2 coins start fake normal H H H T p( Fake H) p( Nrml H) p(h Fake) p(fake) ( 1 ) ( ½ ) = ½ p (H Nrml) p(nrml) ( ½ ) ( ½ ) = ¼ probabilities must sum to 1

12 A little math: Bayes rule P(B A) P(A B) P(B) Example: 2 coins start fake normal Experiment #2: It comes up tails. What is the probability that you re holding the fake? H H H T p( Fake T) p(t Fake) p(fake) ( 0 ) ( ½ ) = 0 = 0 p( Nrml T) p (T Nrml) p(nrml) probabilities must sum to 1 ( ½ ) ( ½ ) = ¼ = 1

13 Is the middle circle popping out or in?

14 P( image OUT & light is above) = 1 P(image IN & Light is below) = 1 Image equally likely to be OUT or IN given sensory data alone What we want to know: P(OUT image) vs. P(IN image) Apply Bayes rule: prior P(OUT image) P(image OUT & light above) P(OUT) P(light above) P(IN image) P(image IN & light below ) P(IN) P(light below) Which of these is greater?

15 Bayesian Models for Perception Bayes rule: P(B A) P(A B) P(B) Formula for computing: P(what s in the world sensory data) (This is what our brain wants to know!) B A P(world sense data) P(sense data world) P(world) Posterior (resulting beliefs about the world) Likelihood (given by laws of physics; ambiguous because many world states could give rise to same sense data) Prior (given by past experience)

16 Helmholtz: perception as optimal inference Perception is our best guess as to what is in the world, given our current sensory evidence and our prior experience. helmholtz P(world sense data) P(sense data world) P(world) Posterior (resulting beliefs about the world) Likelihood (given by laws of physics; ambiguous because many world states could give rise to same sense data) Prior (given by past experience)

17 Helmholtz: perception as optimal inference Perception is our best guess as to what is in the world, given our current sensory evidence and our prior experience. helmholtz P(world sense data) P(sense data world) P(world) Posterior (resulting beliefs about the world) Likelihood (given by laws of physics; ambiguous because many world states could give rise to same sense data) Prior (given by past experience)

18 Many different 3D scenes can give rise to the same 2D retinal image The Ames Room

19 Many different 3D scenes can give rise to the same 2D retinal image The Ames Room A B How does our brain go about deciding which interpretation? P(image A) and P(image B) are equal! (both A and B could have generated this image) Let s use Bayes rule: P(A image) = P(image A) P(A) / Z P(B image) = P(image B) P(B) / Z

20 Hollow Face Illusion

21 Hollow Face Illusion Hypothesis #1: face is concave Hypothesis #2: face is convex P(convex video) P(video convex) P(convex) P(concave video) P(video concave) P(concave) posterior likelihood prior P(convex) > P(concave) posterior probability of convex is higher (which determines our percept)

22 prior belief that objects are convex is SO strong we can t over-ride it, even when we know it s wrong! (So your brain knows Bayes rule even if you don t!)

23 Terminology question: When do we call this a likelihood? A: when considered as a function of x (i.e., with y held fixed) note: doesn t integrate to 1. What s it called as a function of y, for fixed x? conditional distribution or sampling distribution

24 independence

25 independence Definition: x, y are independent iff

26 independence Definition: x, y are independent iff In linear algebra terms: 0 1 (outer product)

27 Summary marginalization (splatting) conditionalization (slicing) Bayes rule (prior, likelihood, posterior) independence

Bayes Formula. MATH 107: Finite Mathematics University of Louisville. March 26, 2014

Bayes Formula. MATH 107: Finite Mathematics University of Louisville. March 26, 2014 Bayes Formula MATH 07: Finite Mathematics University of Louisville March 26, 204 Test Accuracy Conditional reversal 2 / 5 A motivating question A rare disease occurs in out of every 0,000 people. A test

More information

Compute f(x θ)f(θ) dθ

Compute f(x θ)f(θ) dθ Bayesian Updating: Continuous Priors 18.05 Spring 2014 b a Compute f(x θ)f(θ) dθ January 1, 2017 1 /26 Beta distribution Beta(a, b) has density (a + b 1)! f (θ) = θ a 1 (1 θ) b 1 (a 1)!(b 1)! http://mathlets.org/mathlets/beta-distribution/

More information

Classical and Bayesian inference

Classical and Bayesian inference Classical and Bayesian inference AMS 132 Claudia Wehrhahn (UCSC) Classical and Bayesian inference January 8 1 / 11 The Prior Distribution Definition Suppose that one has a statistical model with parameter

More information

Bayesian RL Seminar. Chris Mansley September 9, 2008

Bayesian RL Seminar. Chris Mansley September 9, 2008 Bayesian RL Seminar Chris Mansley September 9, 2008 Bayes Basic Probability One of the basic principles of probability theory, the chain rule, will allow us to derive most of the background material in

More information

Computational Perception. Bayesian Inference

Computational Perception. Bayesian Inference Computational Perception 15-485/785 January 24, 2008 Bayesian Inference The process of probabilistic inference 1. define model of problem 2. derive posterior distributions and estimators 3. estimate parameters

More information

Computer vision: models, learning and inference

Computer vision: models, learning and inference Computer vision: models, learning and inference Chapter 2 Introduction to probability Please send errata to s.prince@cs.ucl.ac.uk Random variables A random variable x denotes a quantity that is uncertain

More information

Probability and Inference

Probability and Inference Deniz Yuret ECOE 554 Lecture 3 Outline 1 Probabilities and ensembles 2 3 Ensemble An ensemble X is a triple (x, A X, P X ), where the outcome x is the value of a random variable, which takes on one of

More information

Some slides from Carlos Guestrin, Luke Zettlemoyer & K Gajos 2

Some slides from Carlos Guestrin, Luke Zettlemoyer & K Gajos 2 Logistics CSE 446: Point Estimation Winter 2012 PS2 out shortly Dan Weld Some slides from Carlos Guestrin, Luke Zettlemoyer & K Gajos 2 Last Time Random variables, distributions Marginal, joint & conditional

More information

Frequentist Statistics and Hypothesis Testing Spring

Frequentist Statistics and Hypothesis Testing Spring Frequentist Statistics and Hypothesis Testing 18.05 Spring 2018 http://xkcd.com/539/ Agenda Introduction to the frequentist way of life. What is a statistic? NHST ingredients; rejection regions Simple

More information

Computational Cognitive Science

Computational Cognitive Science Computational Cognitive Science Lecture 9: A Bayesian model of concept learning Chris Lucas School of Informatics University of Edinburgh October 16, 218 Reading Rules and Similarity in Concept Learning

More information

Probability Theory for Machine Learning. Chris Cremer September 2015

Probability Theory for Machine Learning. Chris Cremer September 2015 Probability Theory for Machine Learning Chris Cremer September 2015 Outline Motivation Probability Definitions and Rules Probability Distributions MLE for Gaussian Parameter Estimation MLE and Least Squares

More information

Math 416 Lecture 2 DEFINITION. Here are the multivariate versions: X, Y, Z iff P(X = x, Y = y, Z =z) = p(x, y, z) of X, Y, Z iff for all sets A, B, C,

Math 416 Lecture 2 DEFINITION. Here are the multivariate versions: X, Y, Z iff P(X = x, Y = y, Z =z) = p(x, y, z) of X, Y, Z iff for all sets A, B, C, Math 416 Lecture 2 DEFINITION. Here are the multivariate versions: PMF case: p(x, y, z) is the joint Probability Mass Function of X, Y, Z iff P(X = x, Y = y, Z =z) = p(x, y, z) PDF case: f(x, y, z) is

More information

Bayesian Updating with Discrete Priors Class 11, Jeremy Orloff and Jonathan Bloom

Bayesian Updating with Discrete Priors Class 11, Jeremy Orloff and Jonathan Bloom 1 Learning Goals ian Updating with Discrete Priors Class 11, 18.05 Jeremy Orloff and Jonathan Bloom 1. Be able to apply theorem to compute probabilities. 2. Be able to define the and to identify the roles

More information

PHASES OF STATISTICAL ANALYSIS 1. Initial Data Manipulation Assembling data Checks of data quality - graphical and numeric

PHASES OF STATISTICAL ANALYSIS 1. Initial Data Manipulation Assembling data Checks of data quality - graphical and numeric PHASES OF STATISTICAL ANALYSIS 1. Initial Data Manipulation Assembling data Checks of data quality - graphical and numeric 2. Preliminary Analysis: Clarify Directions for Analysis Identifying Data Structure:

More information

An AI-ish view of Probability, Conditional Probability & Bayes Theorem

An AI-ish view of Probability, Conditional Probability & Bayes Theorem An AI-ish view of Probability, Conditional Probability & Bayes Theorem Review: Uncertainty and Truth Values: a mismatch Let action A t = leave for airport t minutes before flight. Will A 15 get me there

More information

10/18/2017. An AI-ish view of Probability, Conditional Probability & Bayes Theorem. Making decisions under uncertainty.

10/18/2017. An AI-ish view of Probability, Conditional Probability & Bayes Theorem. Making decisions under uncertainty. An AI-ish view of Probability, Conditional Probability & Bayes Theorem Review: Uncertainty and Truth Values: a mismatch Let action A t = leave for airport t minutes before flight. Will A 15 get me there

More information

Preliminary Statistics Lecture 2: Probability Theory (Outline) prelimsoas.webs.com

Preliminary Statistics Lecture 2: Probability Theory (Outline) prelimsoas.webs.com 1 School of Oriental and African Studies September 2015 Department of Economics Preliminary Statistics Lecture 2: Probability Theory (Outline) prelimsoas.webs.com Gujarati D. Basic Econometrics, Appendix

More information

Bayesian Analysis (Optional)

Bayesian Analysis (Optional) Bayesian Analysis (Optional) 1 2 Big Picture There are two ways to conduct statistical inference 1. Classical method (frequentist), which postulates (a) Probability refers to limiting relative frequencies

More information

Hypothesis Testing. Testing Hypotheses MIT Dr. Kempthorne. Spring MIT Testing Hypotheses

Hypothesis Testing. Testing Hypotheses MIT Dr. Kempthorne. Spring MIT Testing Hypotheses Testing Hypotheses MIT 18.443 Dr. Kempthorne Spring 2015 1 Outline Hypothesis Testing 1 Hypothesis Testing 2 Hypothesis Testing: Statistical Decision Problem Two coins: Coin 0 and Coin 1 P(Head Coin 0)

More information

HST.582J / 6.555J / J Biomedical Signal and Image Processing Spring 2007

HST.582J / 6.555J / J Biomedical Signal and Image Processing Spring 2007 MIT OpenCourseWare http://ocw.mit.edu HST.582J / 6.555J / 16.456J Biomedical Signal and Image Processing Spring 2007 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms.

More information

Bayesian Updating: Discrete Priors: Spring

Bayesian Updating: Discrete Priors: Spring Bayesian Updating: Discrete Priors: 18.05 Spring 2017 http://xkcd.com/1236/ Learning from experience Which treatment would you choose? 1. Treatment 1: cured 100% of patients in a trial. 2. Treatment 2:

More information

CIS 390 Fall 2016 Robotics: Planning and Perception Final Review Questions

CIS 390 Fall 2016 Robotics: Planning and Perception Final Review Questions CIS 390 Fall 2016 Robotics: Planning and Perception Final Review Questions December 14, 2016 Questions Throughout the following questions we will assume that x t is the state vector at time t, z t is the

More information

SYDE 372 Introduction to Pattern Recognition. Probability Measures for Classification: Part I

SYDE 372 Introduction to Pattern Recognition. Probability Measures for Classification: Part I SYDE 372 Introduction to Pattern Recognition Probability Measures for Classification: Part I Alexander Wong Department of Systems Design Engineering University of Waterloo Outline 1 2 3 4 Why use probability

More information

Data Modeling & Analysis Techniques. Probability & Statistics. Manfred Huber

Data Modeling & Analysis Techniques. Probability & Statistics. Manfred Huber Data Modeling & Analysis Techniques Probability & Statistics Manfred Huber 2017 1 Probability and Statistics Probability and statistics are often used interchangeably but are different, related fields

More information

Bayesian Updating with Continuous Priors Class 13, Jeremy Orloff and Jonathan Bloom

Bayesian Updating with Continuous Priors Class 13, Jeremy Orloff and Jonathan Bloom Bayesian Updating with Continuous Priors Class 3, 8.05 Jeremy Orloff and Jonathan Bloom Learning Goals. Understand a parameterized family of distributions as representing a continuous range of hypotheses

More information

Notes on Probability

Notes on Probability Notes on Probability Mark Schmidt January 7, 2017 1 Probabilites Consider an event A that may or may not happen. For example, if we roll a dice then we may or may not roll a 6. We use the notation p(a)

More information

Basics on Probability. Jingrui He 09/11/2007

Basics on Probability. Jingrui He 09/11/2007 Basics on Probability Jingrui He 09/11/2007 Coin Flips You flip a coin Head with probability 0.5 You flip 100 coins How many heads would you expect Coin Flips cont. You flip a coin Head with probability

More information

Bayesian Methods: Naïve Bayes

Bayesian Methods: Naïve Bayes Bayesian Methods: aïve Bayes icholas Ruozzi University of Texas at Dallas based on the slides of Vibhav Gogate Last Time Parameter learning Learning the parameter of a simple coin flipping model Prior

More information

Recall from last time. Lecture 3: Conditional independence and graph structure. Example: A Bayesian (belief) network.

Recall from last time. Lecture 3: Conditional independence and graph structure. Example: A Bayesian (belief) network. ecall from last time Lecture 3: onditional independence and graph structure onditional independencies implied by a belief network Independence maps (I-maps) Factorization theorem The Bayes ball algorithm

More information

Lecture 6: Markov Chain Monte Carlo

Lecture 6: Markov Chain Monte Carlo Lecture 6: Markov Chain Monte Carlo D. Jason Koskinen koskinen@nbi.ku.dk Photo by Howard Jackman University of Copenhagen Advanced Methods in Applied Statistics Feb - Apr 2016 Niels Bohr Institute 2 Outline

More information

Inconsistency of Bayesian inference when the model is wrong, and how to repair it

Inconsistency of Bayesian inference when the model is wrong, and how to repair it Inconsistency of Bayesian inference when the model is wrong, and how to repair it Peter Grünwald Thijs van Ommen Centrum Wiskunde & Informatica, Amsterdam Universiteit Leiden June 3, 2015 Outline 1 Introduction

More information

Accouncements. You should turn in a PDF and a python file(s) Figure for problem 9 should be in the PDF

Accouncements. You should turn in a PDF and a python file(s) Figure for problem 9 should be in the PDF Accouncements You should turn in a PDF and a python file(s) Figure for problem 9 should be in the PDF Please do not zip these files and submit (unless there are >5 files) 1 Bayesian Methods Machine Learning

More information

Lecture 9: Naive Bayes, SVM, Kernels. Saravanan Thirumuruganathan

Lecture 9: Naive Bayes, SVM, Kernels. Saravanan Thirumuruganathan Lecture 9: Naive Bayes, SVM, Kernels Instructor: Outline 1 Probability basics 2 Probabilistic Interpretation of Classification 3 Bayesian Classifiers, Naive Bayes 4 Support Vector Machines Probability

More information

Bayesian Inference for Normal Mean

Bayesian Inference for Normal Mean Al Nosedal. University of Toronto. November 18, 2015 Likelihood of Single Observation The conditional observation distribution of y µ is Normal with mean µ and variance σ 2, which is known. Its density

More information

Machine Learning. Bayes Basics. Marc Toussaint U Stuttgart. Bayes, probabilities, Bayes theorem & examples

Machine Learning. Bayes Basics. Marc Toussaint U Stuttgart. Bayes, probabilities, Bayes theorem & examples Machine Learning Bayes Basics Bayes, probabilities, Bayes theorem & examples Marc Toussaint U Stuttgart So far: Basic regression & classification methods: Features + Loss + Regularization & CV All kinds

More information

Review: Statistical Model

Review: Statistical Model Review: Statistical Model { f θ :θ Ω} A statistical model for some data is a set of distributions, one of which corresponds to the true unknown distribution that produced the data. The statistical model

More information

Naïve Bayes classification

Naïve Bayes classification Naïve Bayes classification 1 Probability theory Random variable: a variable whose possible values are numerical outcomes of a random phenomenon. Examples: A person s height, the outcome of a coin toss

More information

Math Review Sheet, Fall 2008

Math Review Sheet, Fall 2008 1 Descriptive Statistics Math 3070-5 Review Sheet, Fall 2008 First we need to know about the relationship among Population Samples Objects The distribution of the population can be given in one of the

More information

Computational Cognitive Science

Computational Cognitive Science Computational Cognitive Science Lecture 8: Frank Keller School of Informatics University of Edinburgh keller@inf.ed.ac.uk Based on slides by Sharon Goldwater October 14, 2016 Frank Keller Computational

More information

Fundamentals. CS 281A: Statistical Learning Theory. Yangqing Jia. August, Based on tutorial slides by Lester Mackey and Ariel Kleiner

Fundamentals. CS 281A: Statistical Learning Theory. Yangqing Jia. August, Based on tutorial slides by Lester Mackey and Ariel Kleiner Fundamentals CS 281A: Statistical Learning Theory Yangqing Jia Based on tutorial slides by Lester Mackey and Ariel Kleiner August, 2011 Outline 1 Probability 2 Statistics 3 Linear Algebra 4 Optimization

More information

STAT J535: Introduction

STAT J535: Introduction David B. Hitchcock E-Mail: hitchcock@stat.sc.edu Spring 2012 Chapter 1: Introduction to Bayesian Data Analysis Bayesian statistical inference uses Bayes Law (Bayes Theorem) to combine prior information

More information

Probability Review Lecturer: Ji Liu Thank Jerry Zhu for sharing his slides

Probability Review Lecturer: Ji Liu Thank Jerry Zhu for sharing his slides Probability Review Lecturer: Ji Liu Thank Jerry Zhu for sharing his slides slide 1 Inference with Bayes rule: Example In a bag there are two envelopes one has a red ball (worth $100) and a black ball one

More information

MAE 493G, CpE 493M, Mobile Robotics. 6. Basic Probability

MAE 493G, CpE 493M, Mobile Robotics. 6. Basic Probability MAE 493G, CpE 493M, Mobile Robotics 6. Basic Probability Instructor: Yu Gu, Fall 2013 Uncertainties in Robotics Robot environments are inherently unpredictable; Sensors and data acquisition systems are

More information

The Naïve Bayes Classifier. Machine Learning Fall 2017

The Naïve Bayes Classifier. Machine Learning Fall 2017 The Naïve Bayes Classifier Machine Learning Fall 2017 1 Today s lecture The naïve Bayes Classifier Learning the naïve Bayes Classifier Practical concerns 2 Today s lecture The naïve Bayes Classifier Learning

More information

Probability & statistics for linguists Class 2: more probability. D. Lassiter (h/t: R. Levy)

Probability & statistics for linguists Class 2: more probability. D. Lassiter (h/t: R. Levy) Probability & statistics for linguists Class 2: more probability D. Lassiter (h/t: R. Levy) conditional probability P (A B) = when in doubt about meaning: draw pictures. P (A \ B) P (B) keep B- consistent

More information

Physics 403. Segev BenZvi. Classical Hypothesis Testing: The Likelihood Ratio Test. Department of Physics and Astronomy University of Rochester

Physics 403. Segev BenZvi. Classical Hypothesis Testing: The Likelihood Ratio Test. Department of Physics and Astronomy University of Rochester Physics 403 Classical Hypothesis Testing: The Likelihood Ratio Test Segev BenZvi Department of Physics and Astronomy University of Rochester Table of Contents 1 Bayesian Hypothesis Testing Posterior Odds

More information

ECE295, Data Assimila0on and Inverse Problems, Spring 2015

ECE295, Data Assimila0on and Inverse Problems, Spring 2015 ECE295, Data Assimila0on and Inverse Problems, Spring 2015 1 April, Intro; Linear discrete Inverse problems (Aster Ch 1 and 2) Slides 8 April, SVD (Aster ch 2 and 3) Slides 15 April, RegularizaFon (ch

More information

Probability Review. Chao Lan

Probability Review. Chao Lan Probability Review Chao Lan Let s start with a single random variable Random Experiment A random experiment has three elements 1. sample space Ω: set of all possible outcomes e.g.,ω={1,2,3,4,5,6} 2. event

More information

Bayesian Networks. Vibhav Gogate The University of Texas at Dallas

Bayesian Networks. Vibhav Gogate The University of Texas at Dallas Bayesian Networks Vibhav Gogate The University of Texas at Dallas Intro to AI (CS 6364) Many slides over the course adapted from either Dan Klein, Luke Zettlemoyer, Stuart Russell or Andrew Moore 1 Outline

More information

Overview of Probability. Mark Schmidt September 12, 2017

Overview of Probability. Mark Schmidt September 12, 2017 Overview of Probability Mark Schmidt September 12, 2017 Dungeons & Dragons scenario: You roll dice 1: Practical Application Roll or you sneak past monster. Otherwise, you are eaten. If you survive, you

More information

STA 291 Lecture 8. Probability. Probability Rules. Joint and Marginal Probability. STA Lecture 8 1

STA 291 Lecture 8. Probability. Probability Rules. Joint and Marginal Probability. STA Lecture 8 1 STA 291 Lecture 8 Probability Probability Rules Joint and Marginal Probability STA 291 - Lecture 8 1 Union and Intersection Let A and B denote two events. The union of two events: A B The intersection

More information

Massachusetts Institute of Technology

Massachusetts Institute of Technology 6.04/6.4: Probabilistic Systems Analysis Fall 00 Quiz Solutions: October, 00 Problem.. 0 points Let R i be the amount of time Stephen spends at the ith red light. R i is a Bernoulli random variable with

More information

DS-GA 1003: Machine Learning and Computational Statistics Homework 7: Bayesian Modeling

DS-GA 1003: Machine Learning and Computational Statistics Homework 7: Bayesian Modeling DS-GA 1003: Machine Learning and Computational Statistics Homework 7: Bayesian Modeling Due: Tuesday, May 10, 2016, at 6pm (Submit via NYU Classes) Instructions: Your answers to the questions below, including

More information

7 Gaussian Discriminant Analysis (including QDA and LDA)

7 Gaussian Discriminant Analysis (including QDA and LDA) 36 Jonathan Richard Shewchuk 7 Gaussian Discriminant Analysis (including QDA and LDA) GAUSSIAN DISCRIMINANT ANALYSIS Fundamental assumption: each class comes from normal distribution (Gaussian). X N(µ,

More information

Naïve Bayes. Jia-Bin Huang. Virginia Tech Spring 2019 ECE-5424G / CS-5824

Naïve Bayes. Jia-Bin Huang. Virginia Tech Spring 2019 ECE-5424G / CS-5824 Naïve Bayes Jia-Bin Huang ECE-5424G / CS-5824 Virginia Tech Spring 2019 Administrative HW 1 out today. Please start early! Office hours Chen: Wed 4pm-5pm Shih-Yang: Fri 3pm-4pm Location: Whittemore 266

More information

Lecture 15. DATA 8 Spring Sampling. Slides created by John DeNero and Ani Adhikari

Lecture 15. DATA 8 Spring Sampling. Slides created by John DeNero and Ani Adhikari DATA 8 Spring 2018 Lecture 15 Sampling Slides created by John DeNero (denero@berkeley.edu) and Ani Adhikari (adhikari@berkeley.edu) Announcements Probability Basics Lowest value: 0 Chance of event that

More information

A PECULIAR COIN-TOSSING MODEL

A PECULIAR COIN-TOSSING MODEL A PECULIAR COIN-TOSSING MODEL EDWARD J. GREEN 1. Coin tossing according to de Finetti A coin is drawn at random from a finite set of coins. Each coin generates an i.i.d. sequence of outcomes (heads or

More information

ECE521 W17 Tutorial 6. Min Bai and Yuhuai (Tony) Wu

ECE521 W17 Tutorial 6. Min Bai and Yuhuai (Tony) Wu ECE521 W17 Tutorial 6 Min Bai and Yuhuai (Tony) Wu Agenda knn and PCA Bayesian Inference k-means Technique for clustering Unsupervised pattern and grouping discovery Class prediction Outlier detection

More information

Discrete Probability and State Estimation

Discrete Probability and State Estimation 6.01, Fall Semester, 2007 Lecture 12 Notes 1 MASSACHVSETTS INSTITVTE OF TECHNOLOGY Department of Electrical Engineering and Computer Science 6.01 Introduction to EECS I Fall Semester, 2007 Lecture 12 Notes

More information

Review: Bayesian learning and inference

Review: Bayesian learning and inference Review: Bayesian learning and inference Suppose the agent has to make decisions about the value of an unobserved query variable X based on the values of an observed evidence variable E Inference problem:

More information

Human-Oriented Robotics. Probability Refresher. Kai Arras Social Robotics Lab, University of Freiburg Winter term 2014/2015

Human-Oriented Robotics. Probability Refresher. Kai Arras Social Robotics Lab, University of Freiburg Winter term 2014/2015 Probability Refresher Kai Arras, University of Freiburg Winter term 2014/2015 Probability Refresher Introduction to Probability Random variables Joint distribution Marginalization Conditional probability

More information

Lecture 02: Summations and Probability. Summations and Probability

Lecture 02: Summations and Probability. Summations and Probability Lecture 02: Overview In today s lecture, we shall cover two topics. 1 Technique to approximately sum sequences. We shall see how integration serves as a good approximation of summation of sequences. 2

More information

18.05 Practice Final Exam

18.05 Practice Final Exam No calculators. 18.05 Practice Final Exam Number of problems 16 concept questions, 16 problems. Simplifying expressions Unless asked to explicitly, you don t need to simplify complicated expressions. For

More information

Naïve Bayes classification. p ij 11/15/16. Probability theory. Probability theory. Probability theory. X P (X = x i )=1 i. Marginal Probability

Naïve Bayes classification. p ij 11/15/16. Probability theory. Probability theory. Probability theory. X P (X = x i )=1 i. Marginal Probability Probability theory Naïve Bayes classification Random variable: a variable whose possible values are numerical outcomes of a random phenomenon. s: A person s height, the outcome of a coin toss Distinguish

More information

Language as a Stochastic Process

Language as a Stochastic Process CS769 Spring 2010 Advanced Natural Language Processing Language as a Stochastic Process Lecturer: Xiaojin Zhu jerryzhu@cs.wisc.edu 1 Basic Statistics for NLP Pick an arbitrary letter x at random from any

More information

Today. Statistical Learning. Coin Flip. Coin Flip. Experiment 1: Heads. Experiment 1: Heads. Which coin will I use? Which coin will I use?

Today. Statistical Learning. Coin Flip. Coin Flip. Experiment 1: Heads. Experiment 1: Heads. Which coin will I use? Which coin will I use? Today Statistical Learning Parameter Estimation: Maximum Likelihood (ML) Maximum A Posteriori (MAP) Bayesian Continuous case Learning Parameters for a Bayesian Network Naive Bayes Maximum Likelihood estimates

More information

Bayesian Concept Learning

Bayesian Concept Learning Learning from positive and negative examples Bayesian Concept Learning Chen Yu Indiana University With both positive and negative examples, it is easy to define a boundary to separate these two. Just with

More information

18.05 Final Exam. Good luck! Name. No calculators. Number of problems 16 concept questions, 16 problems, 21 pages

18.05 Final Exam. Good luck! Name. No calculators. Number of problems 16 concept questions, 16 problems, 21 pages Name No calculators. 18.05 Final Exam Number of problems 16 concept questions, 16 problems, 21 pages Extra paper If you need more space we will provide some blank paper. Indicate clearly that your solution

More information

Rapid Introduction to Machine Learning/ Deep Learning

Rapid Introduction to Machine Learning/ Deep Learning Rapid Introduction to Machine Learning/ Deep Learning Hyeong In Choi Seoul National University 1/32 Lecture 5a Bayesian network April 14, 2016 2/32 Table of contents 1 1. Objectives of Lecture 5a 2 2.Bayesian

More information

Computational Cognitive Science

Computational Cognitive Science Computational Cognitive Science Lecture 9: Bayesian Estimation Chris Lucas (Slides adapted from Frank Keller s) School of Informatics University of Edinburgh clucas2@inf.ed.ac.uk 17 October, 2017 1 / 28

More information

Some Basic Concepts of Probability and Information Theory: Pt. 2

Some Basic Concepts of Probability and Information Theory: Pt. 2 Some Basic Concepts of Probability and Information Theory: Pt. 2 PHYS 476Q - Southern Illinois University January 22, 2018 PHYS 476Q - Southern Illinois University Some Basic Concepts of Probability and

More information

Appendix A : Introduction to Probability and stochastic processes

Appendix A : Introduction to Probability and stochastic processes A-1 Mathematical methods in communication July 5th, 2009 Appendix A : Introduction to Probability and stochastic processes Lecturer: Haim Permuter Scribe: Shai Shapira and Uri Livnat The probability of

More information

CSE 473: Artificial Intelligence

CSE 473: Artificial Intelligence CSE 473: Artificial Intelligence Probability Steve Tanimoto University of Washington [These slides were created by Dan Klein and Pieter Abbeel for CS188 Intro to AI at UC Berkeley. All CS188 materials

More information

CSC321 Lecture 18: Learning Probabilistic Models

CSC321 Lecture 18: Learning Probabilistic Models CSC321 Lecture 18: Learning Probabilistic Models Roger Grosse Roger Grosse CSC321 Lecture 18: Learning Probabilistic Models 1 / 25 Overview So far in this course: mainly supervised learning Language modeling

More information

TDA231. Logistic regression

TDA231. Logistic regression TDA231 Devdatt Dubhashi dubhashi@chalmers.se Dept. of Computer Science and Engg. Chalmers University February 19, 2016 Some data 5 x2 0 5 5 0 5 x 1 In the Bayes classifier, we built a model of each class

More information

{ p if x = 1 1 p if x = 0

{ p if x = 1 1 p if x = 0 Discrete random variables Probability mass function Given a discrete random variable X taking values in X = {v 1,..., v m }, its probability mass function P : X [0, 1] is defined as: P (v i ) = Pr[X =

More information

Introduction into Bayesian statistics

Introduction into Bayesian statistics Introduction into Bayesian statistics Maxim Kochurov EF MSU November 15, 2016 Maxim Kochurov Introduction into Bayesian statistics EF MSU 1 / 7 Content 1 Framework Notations 2 Difference Bayesians vs Frequentists

More information

Intro to Probability Instructor: Alexandre Bouchard

Intro to Probability Instructor: Alexandre Bouchard www.stat.ubc.ca/~bouchard/courses/stat302-sp2017-18/ Intro to Probability Instructor: Alexandre Bouchard Announcements Graded midterm available after lecture Webwork due tonight Regrading policy IF you

More information

COMP 328: Machine Learning

COMP 328: Machine Learning COMP 328: Machine Learning Lecture 2: Naive Bayes Classifiers Nevin L. Zhang Department of Computer Science and Engineering The Hong Kong University of Science and Technology Spring 2010 Nevin L. Zhang

More information

Machine Learning CMPT 726 Simon Fraser University. Binomial Parameter Estimation

Machine Learning CMPT 726 Simon Fraser University. Binomial Parameter Estimation Machine Learning CMPT 726 Simon Fraser University Binomial Parameter Estimation Outline Maximum Likelihood Estimation Smoothed Frequencies, Laplace Correction. Bayesian Approach. Conjugate Prior. Uniform

More information

LEARNING WITH BAYESIAN NETWORKS

LEARNING WITH BAYESIAN NETWORKS LEARNING WITH BAYESIAN NETWORKS Author: David Heckerman Presented by: Dilan Kiley Adapted from slides by: Yan Zhang - 2006, Jeremy Gould 2013, Chip Galusha -2014 Jeremy Gould 2013Chip Galus May 6th, 2016

More information

Which coin will I use? Which coin will I use? Logistics. Statistical Learning. Topics. 573 Topics. Coin Flip. Coin Flip

Which coin will I use? Which coin will I use? Logistics. Statistical Learning. Topics. 573 Topics. Coin Flip. Coin Flip Logistics Statistical Learning CSE 57 Team Meetings Midterm Open book, notes Studying See AIMA exercises Daniel S. Weld Daniel S. Weld Supervised Learning 57 Topics Logic-Based Reinforcement Learning Planning

More information

Lecture 1: Probability Fundamentals

Lecture 1: Probability Fundamentals Lecture 1: Probability Fundamentals IB Paper 7: Probability and Statistics Carl Edward Rasmussen Department of Engineering, University of Cambridge January 22nd, 2008 Rasmussen (CUED) Lecture 1: Probability

More information

COMP 551 Applied Machine Learning Lecture 19: Bayesian Inference

COMP 551 Applied Machine Learning Lecture 19: Bayesian Inference COMP 551 Applied Machine Learning Lecture 19: Bayesian Inference Associate Instructor: (herke.vanhoof@mcgill.ca) Class web page: www.cs.mcgill.ca/~jpineau/comp551 Unless otherwise noted, all material posted

More information

INTRODUCTION TO BAYESIAN INFERENCE PART 2 CHRIS BISHOP

INTRODUCTION TO BAYESIAN INFERENCE PART 2 CHRIS BISHOP INTRODUCTION TO BAYESIAN INFERENCE PART 2 CHRIS BISHOP Personal Healthcare Revolution Electronic health records (CFH) Personal genomics (DeCode, Navigenics, 23andMe) X-prize: first $10k human genome technology

More information

Bayesian Approaches Data Mining Selected Technique

Bayesian Approaches Data Mining Selected Technique Bayesian Approaches Data Mining Selected Technique Henry Xiao xiao@cs.queensu.ca School of Computing Queen s University Henry Xiao CISC 873 Data Mining p. 1/17 Probabilistic Bases Review the fundamentals

More information

Be able to define the following terms and answer basic questions about them:

Be able to define the following terms and answer basic questions about them: CS440/ECE448 Section Q Fall 2017 Final Review Be able to define the following terms and answer basic questions about them: Probability o Random variables, axioms of probability o Joint, marginal, conditional

More information

Bayesian probability theory and generative models

Bayesian probability theory and generative models Bayesian probability theory and generative models Bruno A. Olshausen November 8, 2006 Abstract Bayesian probability theory provides a mathematical framework for peforming inference, or reasoning, using

More information

(1) Introduction to Bayesian statistics

(1) Introduction to Bayesian statistics Spring, 2018 A motivating example Student 1 will write down a number and then flip a coin If the flip is heads, they will honestly tell student 2 if the number is even or odd If the flip is tails, they

More information

Lecture 2: Conjugate priors

Lecture 2: Conjugate priors (Spring ʼ) Lecture : Conjugate priors Julia Hockenmaier juliahmr@illinois.edu Siebel Center http://www.cs.uiuc.edu/class/sp/cs98jhm The binomial distribution If p is the probability of heads, the probability

More information

Lecture 5: Bayes pt. 1

Lecture 5: Bayes pt. 1 Lecture 5: Bayes pt. 1 D. Jason Koskinen koskinen@nbi.ku.dk Photo by Howard Jackman University of Copenhagen Advanced Methods in Applied Statistics Feb - Apr 2016 Niels Bohr Institute 2 Bayes Probabilities

More information

ORF 245 Fundamentals of Statistics Chapter 9 Hypothesis Testing

ORF 245 Fundamentals of Statistics Chapter 9 Hypothesis Testing ORF 245 Fundamentals of Statistics Chapter 9 Hypothesis Testing Robert Vanderbei Fall 2014 Slides last edited on November 24, 2014 http://www.princeton.edu/ rvdb Coin Tossing Example Consider two coins.

More information

Cartesian-product sample spaces and independence

Cartesian-product sample spaces and independence CS 70 Discrete Mathematics for CS Fall 003 Wagner Lecture 4 The final two lectures on probability will cover some basic methods for answering questions about probability spaces. We will apply them to the

More information

Probabilistic and Bayesian Machine Learning

Probabilistic and Bayesian Machine Learning Probabilistic and Bayesian Machine Learning Lecture 1: Introduction to Probabilistic Modelling Yee Whye Teh ywteh@gatsby.ucl.ac.uk Gatsby Computational Neuroscience Unit University College London Why a

More information

Single Maths B: Introduction to Probability

Single Maths B: Introduction to Probability Single Maths B: Introduction to Probability Overview Lecturer Email Office Homework Webpage Dr Jonathan Cumming j.a.cumming@durham.ac.uk CM233 None! http://maths.dur.ac.uk/stats/people/jac/singleb/ 1 Introduction

More information

CS 188: Artificial Intelligence Spring Today

CS 188: Artificial Intelligence Spring Today CS 188: Artificial Intelligence Spring 2006 Lecture 9: Naïve Bayes 2/14/2006 Dan Klein UC Berkeley Many slides from either Stuart Russell or Andrew Moore Bayes rule Today Expectations and utilities Naïve

More information

SAMPLE CHAPTER. Avi Pfeffer. FOREWORD BY Stuart Russell MANNING

SAMPLE CHAPTER. Avi Pfeffer. FOREWORD BY Stuart Russell MANNING SAMPLE CHAPTER Avi Pfeffer FOREWORD BY Stuart Russell MANNING Practical Probabilistic Programming by Avi Pfeffer Chapter 9 Copyright 2016 Manning Publications brief contents PART 1 INTRODUCING PROBABILISTIC

More information

Bayesian Networks BY: MOHAMAD ALSABBAGH

Bayesian Networks BY: MOHAMAD ALSABBAGH Bayesian Networks BY: MOHAMAD ALSABBAGH Outlines Introduction Bayes Rule Bayesian Networks (BN) Representation Size of a Bayesian Network Inference via BN BN Learning Dynamic BN Introduction Conditional

More information

Introduction to Machine Learning. Maximum Likelihood and Bayesian Inference. Lecturers: Eran Halperin, Lior Wolf

Introduction to Machine Learning. Maximum Likelihood and Bayesian Inference. Lecturers: Eran Halperin, Lior Wolf 1 Introduction to Machine Learning Maximum Likelihood and Bayesian Inference Lecturers: Eran Halperin, Lior Wolf 2014-15 We know that X ~ B(n,p), but we do not know p. We get a random sample from X, a

More information

Introduction to Probability and Statistics (Continued)

Introduction to Probability and Statistics (Continued) Introduction to Probability and Statistics (Continued) Prof. icholas Zabaras Center for Informatics and Computational Science https://cics.nd.edu/ University of otre Dame otre Dame, Indiana, USA Email:

More information