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Linear Regression, Machine learning term | PPTX
S.Rulez Study 1
Machine Learning / Linear Regression
Machine Learning
• Limitations of explicit programming
• Spam filter: many rules
• Automatic driving: too many rules
• Machine learning
"Field of study that gives computers the ability to learn without being
explicitly programmed” Arthur Samuel (1959)
Supervised/Unsupervised learning
• Supervised learning
• Teach the computer how to do something, then let it use it;s new
found knowledge to do it
• Unsupervised learning
• Let the computer learn how to do something, and use this to
determine structure and patterns in data
Supervised learning
• Given the “right answer” for each example in the data.
• learning with labeled examples - training set
Unsupervised learning
• In unsupervised learning, we get unlabeled data
• Just told - here is a data set, can you structure it
• To cluster data into to groups - clustering algorithm
• Example of clustering algorithm
• Google news
• Genomics
• Organize computer clusters
• Social network analysis - Customer data
Types of supervised learning
• Predicting final exam score based on time spent
• regression
• Pass/non-pass based on time spent
• binary classification
• Letter grade (A, B, C, E and F) based on time spent
• multi-label classification
Regression
• a statistical process for estimating the relationships among variables.
• 관찰된 연속형 변수들에 대해 두 변수 사이의 모형을 구한 뒤 적합도를 측
정해 내는 분석 방법
Linear Regression
• 종속 변수 y와 한 개 이상의 독립 변수 X와의 선형 상관 관계를 모델링
• 독립 변수는 입력값이나 원인, 종속 변수는 결과물이나 효과를 뜻함
Regression (presentation)
(Linear) Hypothesis
Hypothesis
• It is like your prediction machine, throw in an x value, get a
putative y value
Cost function
• How fit the line to our (training) data
• 기대치와 실제 값의 차이를 구하면 되나, 계산의 편의를 위해 차이의
제곱을 구함
• 각 값의 차이의 제곱의 합을 나누어 평균을 구한다.
Goal: Minimize cost
Hypothesis and Cost
What cost(W) looks like?
How to minimize cost?
Gradient descent algorithm
• Minimize cost function
• Gradient descent is used many minimization problems
• For a given cost function, cost (W, b), it will find W, b to minimize cost
• It can be applied to more general function: cost (w1, w2, …)
Formal definition
Formal definition
Gradient descent algorithm

Linear Regression, Machine learning term

  • 1.
    S.Rulez Study 1 MachineLearning / Linear Regression
  • 2.
    Machine Learning • Limitationsof explicit programming • Spam filter: many rules • Automatic driving: too many rules • Machine learning "Field of study that gives computers the ability to learn without being explicitly programmed” Arthur Samuel (1959)
  • 3.
    Supervised/Unsupervised learning • Supervisedlearning • Teach the computer how to do something, then let it use it;s new found knowledge to do it • Unsupervised learning • Let the computer learn how to do something, and use this to determine structure and patterns in data
  • 4.
    Supervised learning • Giventhe “right answer” for each example in the data. • learning with labeled examples - training set
  • 5.
    Unsupervised learning • Inunsupervised learning, we get unlabeled data • Just told - here is a data set, can you structure it • To cluster data into to groups - clustering algorithm • Example of clustering algorithm • Google news • Genomics • Organize computer clusters • Social network analysis - Customer data
  • 6.
    Types of supervisedlearning • Predicting final exam score based on time spent • regression • Pass/non-pass based on time spent • binary classification • Letter grade (A, B, C, E and F) based on time spent • multi-label classification
  • 7.
    Regression • a statisticalprocess for estimating the relationships among variables. • 관찰된 연속형 변수들에 대해 두 변수 사이의 모형을 구한 뒤 적합도를 측 정해 내는 분석 방법
  • 8.
    Linear Regression • 종속변수 y와 한 개 이상의 독립 변수 X와의 선형 상관 관계를 모델링 • 독립 변수는 입력값이나 원인, 종속 변수는 결과물이나 효과를 뜻함
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    Hypothesis • It islike your prediction machine, throw in an x value, get a putative y value
  • 12.
    Cost function • Howfit the line to our (training) data • 기대치와 실제 값의 차이를 구하면 되나, 계산의 편의를 위해 차이의 제곱을 구함 • 각 값의 차이의 제곱의 합을 나누어 평균을 구한다.
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    Gradient descent algorithm •Minimize cost function • Gradient descent is used many minimization problems • For a given cost function, cost (W, b), it will find W, b to minimize cost • It can be applied to more general function: cost (w1, w2, …)
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