Meetings

1-5-20: For the time being meetings are Wednesdays 10.30 by Zoom.

Group meetings are on Thursday at 11am in Frank Adams 1. If you would like to give a presentation please contact Stephanie Lai.

Group photo (March 2020)

Forthcoming Meetings

 

Past Meetings

Wednesday September 30, 2020

Marcus Webb on “Abstract Krylov Methods and Fast Adaptive Poisson Solvers”.

Wednesday September 16, 2020

Mantas Mikaitis on “Specification of a new MATLAB matrix collection”.

Friday September 11, 2020

Theo Mary on “Mixed Precision Low Rank Compression of Data Sparse Matrices”.

Abstract: Modern hardware increasingly supports low precision arithmetics, that provide unprecedented speed, communication, and energy benefits. Mixed precision algorithms are being developed that combine these lower precision arithmetics with higher precision ones, so as to avoid compromising the accuracy of the computations. In this talk, we present an approach to compute low rank approximations with multiple precisions. For low rank matrices with rapidly decaying singular values, we show that only a fraction of the entries need to be stored in the higher, target precision. We apply this idea to the compression of data sparse matrices, which possess a block low rank structure, and obtain significant gains in storage for a variety of applications. We conclude by discussing ongoing research on how to factorize data sparse matrices in mixed precision.