From cd04017adcdbcff464f3bb03d583acb7eb1b1b8f Mon Sep 17 00:00:00 2001
From: Thomas Gibson <gibsonthomas1120@hotmail.com>
Date: Thu, 13 May 2021 15:40:12 -0500
Subject: [PATCH] Add op.h_max_from_volume
---
grudge/op.py | 27 +++++++++++++++++++++++++++
test/test_grudge.py | 20 +++++---------------
2 files changed, 32 insertions(+), 15 deletions(-)
diff --git a/grudge/op.py b/grudge/op.py
index 48abd914..dbc819ac 100644
--- a/grudge/op.py
+++ b/grudge/op.py
@@ -3,6 +3,7 @@
.. autofunction:: nodes
.. autofunction:: normal
+.. autofunction:: h_max_from_volume
.. autofunction:: local_grad
.. autofunction:: local_d_dx
@@ -153,6 +154,32 @@ def normal(dcoll, dd):
actx = dcoll.discr_from_dd(dd)._setup_actx
return freeze(normal(actx, dcoll, dd))
+
+@memoize_on_first_arg
+def h_max_from_volume(dcoll, dim=None, dd=None):
+ """Returns a characteristic length based on the volume of the elements.
+ This length may not be representative if the elements have very high
+ aspect ratios.
+
+ :arg dcoll: a :class:`grudge.discretization.DiscretizationCollection`.
+ :arg dim: an integer denoting topological dimension. If *None*, the
+ spatial dimension specified by :attr:`dcoll.dim` is used.
+ :arg dd: a :class:`~grudge.dof_desc.DOFDesc`, or a value convertible to one.
+ Defaults to the base volume discretization if not provided.
+ :returns: an integer denoting the characteristic length.
+ """
+ if dd is None:
+ dd = dof_desc.DD_VOLUME
+ dd = dof_desc.as_dofdesc(dd)
+
+ if dim is None:
+ dim = dcoll.dim
+
+ ones_volm = dcoll._volume_discr.zeros(dcoll._setup_actx) + 1.0
+ return nodal_max(
+ dcoll, dd, elementwise_sum(dcoll, mass(dcoll, dd, ones_volm))
+ ) ** (1.0 / dim)
+
# }}}
diff --git a/test/test_grudge.py b/test/test_grudge.py
index 9ab956ee..ec478c08 100644
--- a/test/test_grudge.py
+++ b/test/test_grudge.py
@@ -249,11 +249,8 @@ def test_mass_surface_area(actx_factory, name):
# }}}
- # {{{ compute h_max using mass weights
-
- h_max = actx.np.max(flattened_mass_weights) ** (1/dcoll.dim)
-
- # }}}
+ # compute max element size
+ h_max = op.h_max_from_volume(dcoll)
eoc.add_data_point(h_max, area_error)
@@ -315,13 +312,8 @@ def test_surface_mass_operator_inverse(actx_factory, name):
# }}}
- # {{{ compute h_max from mass weights
-
- ones_volm = volume_discr.zeros(actx) + 1
- flattened_mass_weights = flatten(op.mass(dcoll, dd, ones_volm))
- h_max = actx.np.max(flattened_mass_weights) ** (1/dcoll.dim)
-
- # }}}
+ # compute max element size
+ h_max = op.h_max_from_volume(dcoll)
eoc.add_data_point(h_max, inv_error)
@@ -630,9 +622,7 @@ def test_surface_divergence_theorem(actx_factory, mesh_name, visualize=False):
logger.info("errors: global %.5e local %.5e", err_global, err_local)
# compute max element size
- ones_volm = volume.zeros(actx) + 1
- sum_mass_weights = op.elementwise_sum(dcoll, op.mass(dcoll, dd, ones_volm))
- h_max = op.nodal_max(dcoll, dd, sum_mass_weights) ** (1/dcoll.dim)
+ h_max = op.h_max_from_volume(dcoll)
eoc_global.add_data_point(h_max, err_global)
eoc_local.add_data_point(h_max, err_local)
--
GitLab