First–order accurate monotone conservative schemes have good
convergence and stability properties, and thus play a very
important role in designing modern high resolution shock-capturing
schemes.
Do the monotone difference approximations always
give a good numerical solution in sense of monotonicity preservation
or suppression of oscillations? This note will investigate this problem
from a numerical point of view and show that
a (2K+1)-point monotone scheme may give an oscillatory solution
even though the approximate solution is total variation diminishing, and
satisfies maximum principle as well as discrete entropy inequality.