feat: node/element selection commands returning selected ids (#3636)

* feat: changes to source code

* chore: adding changelog file 3636.miscellaneous.md [dependabot-skip]

* ci: auto fixes from pre-commit.com hooks.

for more information, see https://pre-commit.ci

* chore: adding changelog file 3636.documentation.md [dependabot-skip]

* ci: auto fixes from pre-commit.com hooks.

for more information, see https://pre-commit.ci

* chore: adding changelog file 3636.miscellaneous.md [dependabot-skip]

* feat: added unit tests

---------

Co-authored-by: pyansys-ci-bot <92810346+pyansys-ci-bot@users.noreply.github.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: German <28149841+germa89@users.noreply.github.com>

doc/changelog.d/3636.miscellaneous.md

@@ -0,0 +1 @@
+feat: node/element selection commands returning selected ids

src/ansys/mapdl/core/commands.py

@@ -193,6 +193,8 @@
     "LSEL",
     "ASEL",
     "VSEL",
+    "ESLN",
+    "NSLE",
 ]
 
 

src/ansys/mapdl/core/mapdl_core.py

@@ -1321,6 +1321,10 @@ def wrap_xsel_function_output(method):
                     return self.geometry.anum
                 elif name == "VSEL":
                     return self.geometry.vnum
+                elif name == "ESLN":
+                    return self.mesh.enum
+                elif name == "NSLE":
+                    return self.mesh.nnum
                 else:
                     return None
 

tests/conftest.py

@@ -1157,6 +1157,24 @@ def create_geometry(mapdl):
     return areas, keypoints
 
 
+@pytest.fixture(scope="function")
+def two_dimensional_mesh(mapdl, cleared):
+    length = 4
+    height = 1
+    thickness = 0.2
+    mesh_size = 0.1
+
+    mapdl.prep7()
+
+    mapdl.r(r1=thickness)
+    mapdl.et(1, "PLANE182", kop3=3, kop6=0)
+    mapdl.rectng(0, length, 0, height)
+    mapdl.mshkey(1)
+    mapdl.mshape(0, "2D")
+    mapdl.esize(mesh_size)
+    mapdl.amesh("ALL")
+
+
 @pytest.fixture
 def query(mapdl, cleared):
     return mapdl.queries

tests/test_mesh_grpc.py

@@ -317,3 +317,42 @@ def test_nodal_rotation(mapdl, cleared):
         ]
     )
     assert np.allclose(nrotation_ref, nrotations[:7, :])
+
+
+def test_esln(mapdl, two_dimensional_mesh):
+    mapdl.nsel("S", "LOC", "X", 0)
+    selected_ids = mapdl.esln("S", 0)
+    expected_selected_ids = np.array([1, 41, 81, 121, 161, 201, 241, 281, 321, 361])
+    assert all(selected_ids == expected_selected_ids)
+
+
+def test_nsle(mapdl, two_dimensional_mesh):
+    mapdl.esel("S", "CENT", "X", 0, 0.1)
+    selected_ids = mapdl.nsle("S")
+    expected_selected_ids = np.array(
+        [
+            1,
+            3,
+            52,
+            91,
+            92,
+            93,
+            94,
+            95,
+            96,
+            97,
+            98,
+            99,
+            100,
+            101,
+            102,
+            103,
+            104,
+            105,
+            106,
+            107,
+            108,
+            109,
+        ]
+    )
+    assert all(selected_ids == expected_selected_ids)