Package org.apache.sysds.hops.estim
Class EstimatorSample
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- org.apache.sysds.hops.estim.SparsityEstimator
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- org.apache.sysds.hops.estim.EstimatorSample
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public class EstimatorSample extends SparsityEstimator
This estimator implements an approach based on row/column sampling Yongyang Yu, MingJie Tang, Walid G. Aref, Qutaibah M. Malluhi, Mostafa M. Abbas, Mourad Ouzzani: In-Memory Distributed Matrix Computation Processing and Optimization. ICDE 2017: 1047-1058 The basic idea is to draw random samples of aligned columns SA and rows SB, and compute the output nnz as max(nnz(SA_i)*nnz(SB_i)). However, this estimator is biased toward underestimation as the maximum is unlikely sampled and collisions are not accounted for. Accordingly, we also support an extended estimator that relies on similar ideas for element-wise addition as the other estimators.
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Nested Class Summary
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Nested classes/interfaces inherited from class org.apache.sysds.hops.estim.SparsityEstimator
SparsityEstimator.OpCode
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Field Summary
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Fields inherited from class org.apache.sysds.hops.estim.SparsityEstimator
MIN_PAR_THRESHOLD, MULTI_THREADED_BUILD, MULTI_THREADED_ESTIM
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Constructor Summary
Constructors Constructor Description EstimatorSample()EstimatorSample(double sampleFrac)EstimatorSample(double sampleFrac, boolean extended)
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description DataCharacteristicsestim(MMNode root)Estimates the output sparsity of a DAG of matrix multiplications for the given operator graph of a single root node.doubleestim(MatrixBlock m, SparsityEstimator.OpCode op)Estimates the output sparsity for a given unary operation.doubleestim(MatrixBlock m1, MatrixBlock m2)Estimates the output sparsity for a single matrix multiplication.doubleestim(MatrixBlock m1, MatrixBlock m2, SparsityEstimator.OpCode op)Estimates the output sparsity for a given binary operation.
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Method Detail
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estim
public DataCharacteristics estim(MMNode root)
Description copied from class:SparsityEstimatorEstimates the output sparsity of a DAG of matrix multiplications for the given operator graph of a single root node.- Specified by:
estimin classSparsityEstimator- Parameters:
root- DAG root node- Returns:
- output data characteristics
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estim
public double estim(MatrixBlock m1, MatrixBlock m2)
Description copied from class:SparsityEstimatorEstimates the output sparsity for a single matrix multiplication.- Specified by:
estimin classSparsityEstimator- Parameters:
m1- left-hand-side operandm2- right-hand-side operand- Returns:
- sparsity
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estim
public double estim(MatrixBlock m1, MatrixBlock m2, SparsityEstimator.OpCode op)
Description copied from class:SparsityEstimatorEstimates the output sparsity for a given binary operation.- Specified by:
estimin classSparsityEstimator- Parameters:
m1- left-hand-side operandm2- right-hand-side operandop- operator code- Returns:
- sparsity
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estim
public double estim(MatrixBlock m, SparsityEstimator.OpCode op)
Description copied from class:SparsityEstimatorEstimates the output sparsity for a given unary operation.- Specified by:
estimin classSparsityEstimator- Parameters:
m- left-hand-side operandop- operator code- Returns:
- sparsity
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