• Data types
• Basic statistics
  
  • summary statistics
  • correlations
  • stratified sampling
  • hypothesis testing
  • random data generation
    
    
• Classification and regression
  
  • linear models (SVMs, logistic regression, linear regression)
  • naive Bayes
  • decision trees
  • ensembles of trees (Random Forests and Gradient-Boosted Trees)
  • isotonic regression
    
    
• Collaborative filtering
  
  • alternating least squares (ALS)
    
    
• Clustering
  
  • k-means
  • Gaussian mixture
  • power iteration clustering (PIC)
  • latent Dirichlet allocation (LDA)
  • streaming k-means
    
    
• Dimensionality reduction
  
  • singular value decomposition (SVD)
  • principal component analysis (PCA)
    
    
• Feature extraction and transformation
• Frequent pattern mining
  
  • FP-growth
    
    
• Optimization (developer)
  
  • stochastic gradient descent
  • limited-memory BFGS (L-BFGS)
    

怎样的情况下用Library就够了，怎样的情况下用Library还不够？