Dear all,

in step 9 it is stated that if solution be H1, then we may have lowwer
dimensional singularites and concentration of grid near them without
reduction of estimator (if we use 2nd derivative based error estimators).

My question:


- which kind of estimator we should use in this cases?


- it seems that refinment around singularity is a feasible, becasue we have
concentration of information around them, e.g. when we have a point
singularity be refinement we explore details of local solution structure, so
we expct decrease of l2-norm, though estimator does not decrease, also at
least most of estimators refine grid in the vicinity of singularities, any
comment on this issue?


- why estimator does not decrease? because at least (theoritically) we
compute a measure of estimator inside grid and so lower dimansional features
can not have contribution in integral, am i miss something?


also i have another kind question: it is well known that (at least proved
for some specific problems) interpolation error make a bound for
discritization error, so it can be considered as an error estimator (though
is not very common, else for anisotorpic refinement), what is drawback of
using such estimations?


Cheers

RT
_______________________________________________

Reply via email to