I have few conceptual questions concerning FEM -all are conceptual and their answers might be intertwined hence I ask all in 1 post-:
What FEM does on top of NDSolve? Because NDSolve already divide the domain on a mesh . Here some triggers which automatically activating a FEM solver explained. Sometimes FEM is also used in more detail as in this question - great title btw- as well.
When I solve a system of PDE's by NDSolve, would writing everything from scratch with
NDSolve`FEM`be a valid way of crosscheck? Or should one prefer MATLAB or FEniCS for crosschecking?
Without getting in too much theory, where can I learn FEM with application? I want to learn how to use it properly, including dealing with convergence problems or choosing the correct primary space for a type of equation. Also I checked Wolfram archives for MMA but couldn't come across with something up to date.
Thank you for your time.