Uri Ascher is a Professor of Computer Science at the University of British Columbia in Vancouver, Canada. He has previously co-authored three other books, published by SIAM, as well as many research papers in the general area of numerical methods and their applications. He is a SIAM Fellow and a recipient of the CAIMS Research Prize.Chen Greif is an Associate Professor of Computer Science at the University of British Columbia in Vancouver, Canada. His research interests are in the field of scientific computing, with specialization in numerical linear algebra. He is currently an associate editor of the SIAM Journal on Scientific Computing.