This book contains the Proceedings of the seventh EPSRC Numerical Analysis Summer School, held in 1996. Five major topics in numerical analysis are treated by world experts at a level which should be suitable for first year graduate students and experienced researchers alike, assuming only the knowledge acquired from a first degree in mathematics or in a scientific discipline with significant mathematical content. Often researchers need to obtain an up-to-date picture of work in an area with a substantial literature, either to avoid reproducing work which is already done, or to apply to their own research in a different subject. This book avoids the need to trawl through the literature by presenting important recent results together with references to all the main papers. Each contributor reviews the state of the art in his area, presenting new and often hitherto unpublished material.