Signed Feature Hashing
Inspect signed collision errors and verify inner products are preserved in expectation.
Free theory articleInspect signed collision errors and verify inner products are preserved in expectation.
Concept & interpretation
Feature hashing (the hashing trick) reduces the dimensionality of categorical or high-dimensional features by applying a hash function to feature indices. To unbiasedly preserve inner products, signed feature hashing introduces an additional sign hash function.
Experiment
Explore how different sign patterns and hash sizes affect collision errors. See the interactive Signed Feature Hashing module.
- Change the Vectors input to see how sparsity and correlation affect expected values.
- Adjust the Hash map to scramble the feature indices and see different collisions.
- Modify the Signs pattern or the number of Buckets.
- Observe the Signed collision error and the changes in the visual mapping diagram.