Many books have been written on ?nite difference methods (FDM), but
there are good reasons to write still another one. The main reason is
that even if higher order methods have been known for a long time, the
analysis of stability, accuracy and effectiveness is missing to a large
extent. For example, the de?nition of the formal high order accuracy is
based on the assumption that the true solution is smooth, or expressed
differently, that the grid is ?ne enough such that all variations in the
solution are well resolved. In many applications, this assumption is not
ful?lled, and then it is interesting to know if a high order method is
still effective. Another problem that needs thorough analysis is the
construction of boundary conditions such that both accuracy and
stability is upheld. And ?nally, there has been quite a
strongdevelopmentduringthe last years, inparticularwhenit comesto
verygeneral and stable difference operators for application on
initial-boundary value problems. The content of the book is not purely
theoretical, neither is it a set of recipes for varioustypesof
applications. The idea is to give an overviewof the basic theoryand
constructionprinciplesfor differencemethodswithoutgoing into all
details. For - ample, certain theorems are presented, but the proofs are
in most cases left out. The explanation and application of the theory is
illustrated by using simple model - amples.