use template thus no use for mesh.cpp
use template to deal with different solving systems
rewrite with template, merge .cpp files with .h files
define problem parameters for the FEM solving system
update README.md
define problem parameters for the DG solving system
rewrite with template and modified output format
a Discontinuous Galerkin solving system
seperate Problem class and MyProblem class, change the latter to DGProblem and FEMProblem
rewrite with template
rewrite with template
update Makefile
matlab code to visualize the result