Computing Low-Rank Approximation of a Dense Matrix on Multicore CPUs with a GPU and Its Application to Solving a Hierarchically Semiseparable Linear System of Equations

Algorithm 4

Hybrid algorithms.

Hybrid-I to solve task-1

  repeat

    pivot “best” column among to

    Golub-I

    pivot “worst” column among to

    Chan-II

  until no column pivot occurred

Hybrid-II to solve task-2

  repeat

    pivot “best” column among to

    Chan-II

    pivot “worst” column among to

    Golub-I

  until no column pivot occurred

Hybrid-III to solve both task-1 and task-2

 Hybrid-I , to address task-1

 Hybrid-II , to address task-2