Support Vector Machines Alex Leblang and Sam Birch ML Framework - - PowerPoint PPT Presentation

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Support Vector Machines Alex Leblang and Sam Birch ML Framework - - PowerPoint PPT Presentation

Support Vector Machines Alex Leblang and Sam Birch ML Framework Data projected into feature space, each feature is a dimension. Via Wikipedia, scikit-learn examples SVMs Supervised learning model: train / test Binary, discriminative


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Support Vector Machines

Alex Leblang and Sam Birch

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ML Framework

Data projected into feature space, each feature is a dimension.

Via Wikipedia, scikit-learn examples

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SVMs

  • Supervised learning model: train / test
  • Binary, discriminative classifier

○ Models the boundary, not the data

  • Linear classification boundary defined with

support vectors

  • Non-linear decision boundaries can be

introduced via the kernel trick

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Where SVMs fit (Hays)

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Linear separators (Hays)

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Non-linearity (Andrew Moore via Hays)

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Kernel Trick

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Demo

MLDemo

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Challenges

  • Non-linear classification takes > O(n) time

○ Have to compute entire kernel matrix ○ Most large-scale classification tasks use linear SVMs

  • Validation
  • Feature choice is challenging in many

domains

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LibSVM

An efficient implementation of SVM routines Functions in LibSVM:

  • C-Support vector classification
  • V-Support vector classification
  • Distribution Estimation
  • v-Support vector regression
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Optimization

Moving training and classification to the GPU can provide 1-2 orders of magnitude performance advantage “Fast Support Vector Machine Training and Classification on Graphics Processors” (Catanzaro, Sundaram, Keutzer)

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Conclusion

  • Solid go-to classification algorithm
  • Features > specifics
  • Tuning and validation make a big difference