From 1a17d40d3110fb5c058f75bea2de4366f5fa96e4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miguel=20Mas=C3=B3?= <miguel.maso@upc.edu>
Date: Tue, 25 Aug 2026 15:59:52 +0200
Subject: [PATCH 1/2] Added `interpolate_L2_field`

---
 .../ComputationalModels.jl                    |  3 +++
 src/ComputationalModels/PostProcessors.jl     | 20 ++++++++++++++++++-
 src/Exports.jl                                |  2 ++
 3 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/ComputationalModels/ComputationalModels.jl b/src/ComputationalModels/ComputationalModels.jl
index b27f582..c2188ee 100644
--- a/src/ComputationalModels/ComputationalModels.jl
+++ b/src/ComputationalModels/ComputationalModels.jl
@@ -85,5 +85,8 @@ export reset!
 export interpolate_L2_tensor
 export interpolate_L2_vector
 export interpolate_L2_scalar
+export interpolate_L2_field
+export L2_projection
 export L2_Projection
+
 end
diff --git a/src/ComputationalModels/PostProcessors.jl b/src/ComputationalModels/PostProcessors.jl
index 986b606..96f2a76 100644
--- a/src/ComputationalModels/PostProcessors.jl
+++ b/src/ComputationalModels/PostProcessors.jl
@@ -194,9 +194,27 @@ function interpolate_L2_scalar(x, Ω, dΩ, Γ=Ω)
 end
 
 
-function L2_Projection(u, dΩ, V)
+"""
+Interpolate an L2 field into an H1 field.
+"""
+function interpolate_L2_field(x, Ω, dΩ, valuetype)
+  refL2 = ReferenceFE(lagrangian, valuetype, 0)
+  reffe = ReferenceFE(lagrangian, valuetype, 1)
+  VL2 = FESpace(Ω, refL2, conformity=:L2)
+  VH1 = FESpace(Ω, reffe, conformity=:H1)
+  interpolate_everywhere(L2_projection(x, dΩ, VL2), VH1)
+end
+
+
+"""
+Perform an L2 projection of a function `u` onto a finite element
+space `V` defined over the domain `Ω` with measure `dΩ`.
+"""
+function L2_projection(u, dΩ, V)
   a(w, v) = ∫(w ⊙ v) * dΩ
   l(v)    = ∫(v ⊙ u) * dΩ
   op      = AffineFEOperator(a, l, V, V)
   solve(op)
 end
+
+L2_Projection = L2_projection
diff --git a/src/Exports.jl b/src/Exports.jl
index ad033c4..0417462 100644
--- a/src/Exports.jl
+++ b/src/Exports.jl
@@ -165,6 +165,8 @@ end
 @publish ComputationalModels  InterpolableBC
 @publish ComputationalModels  InterpolableBC!
 @publish ComputationalModels  TrialFESpace! # Exporting internal function of Gridap
+@publish ComputationalModels interpolate_L2_field
+@publish ComputationalModels L2_projection
 @publish ComputationalModels  L2_Projection
 
 @publish DiscreteModeling CartesianTags

From 27477190aa3d60765007c0981fa290e5bb0052a4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Miguel=20Mas=C3=B3?= <miguel.maso@upc.edu>
Date: Tue, 25 Aug 2026 16:46:03 +0200
Subject: [PATCH 2/2] inferring field type

---
 src/ComputationalModels/PostProcessors.jl | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/src/ComputationalModels/PostProcessors.jl b/src/ComputationalModels/PostProcessors.jl
index 96f2a76..5a9b5e5 100644
--- a/src/ComputationalModels/PostProcessors.jl
+++ b/src/ComputationalModels/PostProcessors.jl
@@ -194,12 +194,21 @@ function interpolate_L2_scalar(x, Ω, dΩ, Γ=Ω)
 end
 
 
+function get_cell_field_type(f::CellField, dΩ::Measure)
+  pts = get_cell_points(dΩ)
+  f_x = f(pts)
+  T = eltype(Gridap.Arrays.testitem(f_x))
+  return T
+end
+
+
 """
 Interpolate an L2 field into an H1 field.
+The type of the field is inferred from the cell field `x` and the measure `dΩ`.
 """
-function interpolate_L2_field(x, Ω, dΩ, valuetype)
-  refL2 = ReferenceFE(lagrangian, valuetype, 0)
-  reffe = ReferenceFE(lagrangian, valuetype, 1)
+function interpolate_L2_field(x, Ω, dΩ, T::Type=get_cell_field_type(x, dΩ))
+  refL2 = ReferenceFE(lagrangian, T, 0)
+  reffe = ReferenceFE(lagrangian, T, 1)
   VL2 = FESpace(Ω, refL2, conformity=:L2)
   VH1 = FESpace(Ω, reffe, conformity=:H1)
   interpolate_everywhere(L2_projection(x, dΩ, VL2), VH1)