[mlpack-git] [mlpack/mlpack] Modeling LSH For Performance Tuning (#749)

Ryan Curtin notifications at github.com
Tue Aug 30 09:05:58 EDT 2016


> +
> +    // Reference set for kNN
> +    arma::mat refMat = sampleSet.cols(refSetStart, refSetEnd);
> +    referenceSizes(i) = refMat.n_cols;
> +
> +    arma::Mat<size_t> neighbors; // Not going to be used but required.
> +    arma::mat kNNDistances; // What we need.
> +    KNN naive(refMat, true); // true: train and use naive kNN.
> +    naive.Search(queryMat, k, neighbors, kNNDistances);
> +
> +    // Store the squared distances (what we need).
> +    kNNDistances = arma::pow(kNNDistances, 2);
> +
> +    // Compute Arithmetic and Geometric mean of the distances.
> +    Ek.row(i) = arma::mean(kNNDistances.t());
> +    Gk.row(i) = arma::exp(arma::mean(arma::log(kNNDistances.t()), 0));

Ah, ok!  I did not think it through fully. :)

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/mlpack/mlpack/pull/749/files/57c9d5e634d7d3d7e2ca1618353fe37d9e23b34a#r76789998
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.cc.gatech.edu/pipermail/mlpack-git/attachments/20160830/0aeeefc9/attachment-0001.html>


More information about the mlpack-git mailing list