[physics] Remove sph.density()

demos/simple_sph.py

@@ -32,7 +32,7 @@
 def sph_step(v: Field, dt, isotropic_exp=20., base_density=1.):
     graph = sph.neighbor_graph(v.geometry, 'poly6', desired_neighbors=desired_neighbors, compute='kernel', domain=domain)
     # --- compute density and pressure ---
-    rho = sph.density(graph) * particle_mass  # this includes the density contribution from self
+    rho = math.sum(graph.edges['kernel'], dual) * particle_mass  # this includes the density contribution from self
     pressure = isotropic_exp * (rho - base_density)
     nb_rho = rename_dims(rho, instance, dual)
     nb_pressure = rename_dims(pressure, instance, dual)  # warp re-computes this from nb_rho

phi/physics/sph.py

@@ -163,17 +163,17 @@ def evaluate_kernel(delta, distance, h, spatial_rank: int, kernel: str, types: S
     return {t: result[t] for t in types}  # re-order output to match input
 
 
-def density(graph: Graph) -> Tensor:
-    """
-    Sum the kernel function over all neighbors within the support radius.
-
-    Args:
-        graph: `Graph` with `kernel` values stored in the edges.
-
-    Returns:
-        Relative density, i.e. not yet scaled by particle mass.
-    """
-    return math.sum(graph.edges['kernel'], dual)
+# def density(graph: Graph) -> Tensor:
+#     """
+#     Sum the kernel function over all neighbors within the support radius.
+#
+#     Args:
+#         graph: `Graph` with `kernel` values stored in the edges.
+#
+#     Returns:
+#         Relative density, i.e. not yet scaled by particle mass.
+#     """
+#     return math.sum(graph.edges['kernel'], dual)
 
 
 # def diffusion(u: Field):