It is necessary for me to solve a Poisson problem with a numerical method on a square domain with two types of triangular mesh: uniform triangular mesh (using uniform distribution nodes on square) and nonuniform triangular mesh using pdetool in MATLAB.
The first one leads to a banded matrix and the second one leads to a sparse matrix but not banded. This is the only different between two method. It should be noted that the sparsity of two matrices are the same. Also the condition numbers of those are nearlly equal.
But the result by using uniform triangular mesh is much better than the second one. Is there anyone who know about this problem?
Also, I should say the quality of two meshes are same.