Class EstimatorDensityMap

  • public class EstimatorDensityMap
    extends SparsityEstimator
    This estimator implements an approach called density maps, as introduced in David Kernert, Frank Köhler, Wolfgang Lehner: SpMacho - Optimizing Sparse Linear Algebra Expressions with Probabilistic Density Estimation. EDBT 2015: 289-300. The basic idea is to maintain a density matrix per input, i.e., non-zero counts per bxb cells of the matrix, and compute the output density map based on a matrix-multiply-like aggregation of average estimates per cell. The output sparsity is then derived as an aggregate of the output density map, but this density map can also be used for intermediates in chains of matrix multiplications.