"""This implements support for 4th-order accurate finite-volume data
by adding support for converting between cell averages and centers.
"""
from pyro.mesh.patch import CellCenterData2d
[docs]
class FV2d(CellCenterData2d):
"""this is a finite-volume grid. We expect the data to represent
cell-averages, and do operations to 4th order. This assumes dx =
dy
"""
[docs]
def to_centers(self, name):
""" convert variable name from an average to cell-centers """
a = self.get_var(name)
c = self.grid.scratch_array()
ng = self.grid.ng
c[:, :] = a[:, :]
c.v(buf=ng-1)[:, :] = a.v(buf=ng-1) - self.grid.dx**2*a.lap(buf=ng-1)/24.0
return c
[docs]
def from_centers(self, name):
"""treat the stored data as if it lives at cell-centers and convert
it to an average
"""
self.fill_BC(name)
a = self.get_var(name)
a.v()[:, :] = a.v() + self.grid.dx**2*a.lap()/24.0