Zhen's Presentation Slides on enhancements to vw

Zhen Qin's slides describe Zhen's contributions to vowpal wabbit. These include:

• --invert_hash: create readable model including the original feature names
• --holdout_on/off and --holdout_period <N> (default when multiple passes are used)
• --early_terminate: to stop multiple passes when held-out examples loss stops decreasing.
• --bs <N> bootstrap aggregation: model averaging for decreasing model variance and generalization loss
• --top <k>: reduction to top k recommendations
• -q a:, -q ::, -q :a: generalization for "any" in cubic feature crossing
• --feature_mask

See more details in the slides above.