This is a book on the numerical approximation of partial differential equations (PDEs). Its scope is to provide a thorough illustration of numerical methods out their stability and convergence analysis, derive error bounds, and discuss the algorithmic aspects relative to their implementation.  本书为英文版.This is a book on the numerical approximation of partial differential equations (PDEs). Its scope is to provide a thorough illustration of numerical methods out their stability and convergence analysis, derive error bounds, and discuss the algorithmic aspects relative to their implementation. 本书为英文版.