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[BUG] fem.integrate failing with double precision polynomial space vectors #418
Description
Bug Description
fem.integrate is failing with double precision vectors. Updating the fem.make_polynomial_space dtype from wp.vec2 to wp.vec2d causes fem.integrate to fail with the following error:
Module warp.fem.space.restriction.dyn.fill_element_node_indices_Grid2D_BoundarySides_GridBipolynomialSpaceTopology_9_Trace_Whole 25805a8 load on device 'cuda:0' took 0.39 ms (cached)
Module warp.fem.utils 8b39cbb load on device 'cuda:0' took 0.28 ms (cached)
Module warp.fem.space.restriction 4263cdf load on device 'cuda:0' took 0.29 ms (cached)
Module __main__.mass_form e618e55 load on device 'cuda:0' took 30.84 ms
Traceback (most recent call last):
File "/.../lib/python3.11/site-packages/warp/codegen.py", line 1006, in build
adj.eval(adj.tree.body[0])
File "/.../lib/python3.11/site-packages/warp/codegen.py", line 2700, in eval
return emit_node(adj, node)
^^^^^^^^^^^^^^^^^^^^
File "/.../lib/python3.11/site-packages/warp/codegen.py", line 1611, in emit_FunctionDef
adj.eval(f)
File "/.../lib/python3.11/site-packages/warp/codegen.py", line 2700, in eval
return emit_node(adj, node)
^^^^^^^^^^^^^^^^^^^^
File "/.../lib/python3.11/site-packages/warp/codegen.py", line 2558, in emit_Return
var = (adj.eval(node.value),)
^^^^^^^^^^^^^^^^^^^^
File "/.../lib/python3.11/site-packages/warp/codegen.py", line 2700, in eval
return emit_node(adj, node)
^^^^^^^^^^^^^^^^^^^^
File "/.../lib/python3.11/site-packages/warp/codegen.py", line 2238, in emit_Call
args = tuple(adj.resolve_arg(x) for x in node.args)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/.../lib/python3.11/site-packages/warp/codegen.py", line 2238, in <genexpr>
args = tuple(adj.resolve_arg(x) for x in node.args)
^^^^^^^^^^^^^^^^^^
File "/.../lib/python3.11/site-packages/warp/codegen.py", line 2141, in resolve_arg
var = adj.eval(arg)
^^^^^^^^^^^^^
File "/.../lib/python3.11/site-packages/warp/codegen.py", line 2700, in eval
return emit_node(adj, node)
^^^^^^^^^^^^^^^^^^^^
File "/.../lib/python3.11/site-packages/warp/codegen.py", line 2242, in emit_Call
out = adj.add_call(func, args, kwargs, type_args, min_outputs=min_outputs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/.../lib/python3.11/site-packages/warp/codegen.py", line 1324, in add_call
return_type = func.value_func(
^^^^^^^^^^^^^^^^
File "/.../lib/python3.11/site-packages/warp/builtins.py", line 831, in vector_value_func
raise RuntimeError()
.....
raise RuntimeError(
RuntimeError: Error while parsing function "integrate_kernel_fn" at /.../lib/python3.11/site-packages/warp/fem/integrate.py:926:
val = integrand_func(sample, fields, values)
;Error while parsing function "mass_form" at /.../scripts/warp_min.py:13:
return wp.dot(u(s), v(s))
;Error while parsing function "eval_test_inner" at /.../lib/python3.11/site-packages/warp/fem/field/virtual.py:60:
dof_value = self.space.node_basis_element(get_node_coord(dof))
;Error while parsing function "node_basis_element" at /.../lib/python3.11/site-packages/warp/fem/space/basis_function_space.py:90:
return basis_element(self.dof_dtype(0.0), dof_coord)Minimal Example
import warp as wp
import warp.fem as fem
@fem.integrand
def mass_form(
s: fem.Sample,
u: fem.Field,
v: fem.Field,
) -> wp.float64:
"""Mass form for L2 projection of vector fields."""
# For vector fields, we want the dot product of the vectors
return wp.dot(u(s), v(s))
def main():
geo = fem.Grid2D(res=wp.vec2i(3))
boundary = fem.BoundarySides(geo)
# Fails with dtype=wp.vec2d
u_space = fem.make_polynomial_space(geo, degree=2, dtype=wp.vec2d)
# # Passes with dtype=wp.vec2
# u_space = fem.make_polynomial_space(geo, degree=2, dtype=wp.vec2)
u_test = fem.make_test(space=u_space, domain=boundary)
u_trial = fem.make_trial(space=u_space, domain=boundary)
u_projector = fem.integrate(
mass_form, fields={"u": u_trial, "v": u_test}, nodal=True
)
print("Successfully created projector")
if __name__ == "__main__":
wp.init()
main()System Information
Python
- Python 3.11.10
- Poetry package manager
- warp 1.5.0
Hardware and CUDA Version
CUDA Toolkit 12.6, Driver 12.4
Devices:
"cpu" : "x86_64"
"cuda:0" : "NVIDIA L40S" (44 GiB, sm_89, mempool enabled)
Activity
[-][BUG][/-][+][BUG] fem.integrate failing with double precision polynomial space vectors[/+]gdaviet commentedon Jan 8, 2025
Hi @cmflannery, indeed double-precision-valued spaces are not currently supported by
fem.integrate.Currently, the rationale has been to stay in single-precision for quantities evaluated at any single sample point, then switch to double precision to perform accumulation over the different samples.
While this strategy usually gives a good performance vs numerical stability compromise, I understand that there are cases where having the full evaluation done in full precision would be necessary, so support for double-precision fields and geometries is definitely on the roadmap (as well as complex-valued, eventually).
In any case, the error message should be made more indicative of the current limitation
cmflannery commentedon Jan 10, 2025
Gotcha, thanks for the clarification. A more indicative error message would definitely be appreciated!
fem.integrate#440Add geometry-driven fp64 precision support to warp.fem (NVIDIAGH-418)
Reorganize warp.fem tests into warp/tests/fem/ (NVIDIAGH-418)
shi-eric commentedon Apr 14, 2026
@gdaviet added support for double precision in
warp.fema few weeks ago: 9d913f8 this will be released in Warp 1.13 at the start of May.