Add Mesh.add_points(points) and Mesh.clear_points_without_cells() (#947)

* Add `Mesh.add_points(points)` and `Mesh.clear_points_without_cells()`

* Update Examples to use the new mesh-methods

Author: adtzlr

CHANGELOG.md

@@ -3,6 +3,10 @@ All notable changes to this project will be documented in this file. The format
 
 ## [Unreleased]
 
+### Added
+- Add `Mesh.add_points(points)` to update the mesh with additional points.
+- Add `Mesh.clear_points_without_cells()` to clear the list of points without cells (useful for center-points of multi-point constraints).
+
 ## [9.2.0] - 2025-03-04
 
 ### Added

examples/ex08_shear.py

@@ -44,8 +44,8 @@
 a = min(L / n, H / n)
 
 mesh = fem.Rectangle((0, 0), (L, H), n=(round(L / a), round(H / a)))
-mesh.update(points=np.vstack((mesh.points, [L / 2, 1.3 * H])))
-mesh.points_without_cells = np.array([], dtype=bool)
+mesh.add_points([L / 2, 1.3 * H])
+mesh.clear_points_without_cells()
 
 # %%
 # A numeric quad-region created on the mesh in combination with a vector-valued

examples/ex19_taylor-hood.py

@@ -20,7 +20,8 @@
 mesh = fem.Circle(n=6, sections=[0]).triangulate().add_midpoints_edges()
 mask = np.isclose(mesh.x**2 + mesh.y**2, 1, atol=0.05)
 mesh.points[mask] /= np.linalg.norm(mesh.points[mask], axis=1).reshape(-1, 1)
-mesh.update(points=np.vstack([mesh.points, [0, 1.1]]))
+mesh.add_points([0, 1.1])
+mesh.clear_points_without_cells()
 
 # %%
 # Let's create a region for quadratic triangles and a mixed-field container with two

src/felupe/mesh/_mesh.py

@@ -323,6 +323,14 @@ def imshow(self, *args, ax=None, **kwargs):
 
         return ax
 
+    def add_points(self, points):
+        "Add additional points to the mesh."
+        self.update(points=np.vstack([self.points, points]))
+
+    def clear_points_without_cells(self):
+        "Clear the list of points without cells."
+        self.points_without_cells = self.points_without_cells[:0]
+
     def get_point_ids(self, value, fun=np.isclose, mode=np.all, **kwargs):
         """Return point ids for points which are close to a given value.
 

tests/test_mesh.py

@@ -545,6 +545,10 @@ def test_mesh_update():
     mesh.update(points=new_points)
     region.reload(mesh)
 
+    # add additional point and clear points without cells
+    mesh.add_points([2, 0, 0])
+    mesh.clear_points_without_cells()
+
 
 def test_modify_corners():
     fem.Rectangle(n=6).modify_corners()