CylinderSegment online

magpylib · OrtnerMichael · Sep 24, 2025 · Jul 21, 2025 · Jul 21, 2025 · Jul 21, 2025
commit ca6569309ecd2557eeeb30682908e5c580a051c5
diff --git a/_temp_tests.py b/_temp_tests.py
@@ -289,6 +289,32 @@ def test_force_backforward_dipole_cylinder():
         assert errT < err*2, f"Torque mismatch: {errT}"
 
 
+def test_force_backforward_dipole_cylinderSegment():
+    """
+    test backward and forward force on dipole and cylinder
+    test meshing convergence
+    """
+    cylseg = magpy.magnet.CylinderSegment(
+        dimension=(1, 2, 1, 45, 123),
+        polarization=(1.2,2.3,-3.1),
+    ).rotate_from_angax([11, 24.3, 55.2, 76, 20, 10, 15, 20, -123.1234, 1234], axis=(1,2,-3), anchor=(.1,.2,.3))
+    dip = magpy.misc.Dipole(
+        moment=(1.3e3,-1.1e3,2.2e3),
+        position=np.linspace((-5,-.4,-1.3), (3, 1.4, -1.2), 10)
+    )
+
+    F0,T0 = getFT(cylseg, dip, pivot=(0,0,0))
+
+    for meshing,err in zip([20, 360], [1e-1, 1e-2]):
+        cylseg.meshing = meshing
+        F1,T1 = getFT(dip, cylseg, pivot=(0,0,0))
+
+        errF = np.max(np.linalg.norm(F1 + F0, axis=1) / np.linalg.norm(F1 - F0, axis=1))
+        assert errF < err, f"Force mismatch: {errF}"
+        errT = np.max(np.linalg.norm(T1 + T0, axis=1) / np.linalg.norm(T1 - T0, axis=1))
+        assert errT < err*2, f"Torque mismatch: {errT}"
+
+
 
 
 
@@ -2051,6 +2077,7 @@ def test_force_orientation_nightmare():
     test_force_backforward_dipole_sphere()
     test_force_backforward_dipole_cuboid()
     test_force_backforward_dipole_cylinder()
+    test_force_backforward_dipole_cylinderSegment()
 
 
     # object and interface properties

diff --git a/src/magpylib/_src/fields/field_FT.py b/src/magpylib/_src/fields/field_FT.py
@@ -792,7 +792,23 @@ def getFT(sources, targets, pivot="centroid", eps=1e-5, squeeze=True, meshreport
 
 if __name__ == "__main__":
     import magpylib as magpy
+    cylseg = magpy.magnet.CylinderSegment(
+        dimension=(1, 2, 1, 45, 123),
+        polarization=(1.2,2.3,-3.1),
+    ).rotate_from_angax([11, 24.3, 55.2, 76, 20, 10, 15, 20, -123.1234, 1234], axis=(1,2,-3), anchor=(.1,.2,.3))
+    dip = magpy.misc.Dipole(
+        moment=(1.3e3,-1.1e3,2.2e3),
+        position=np.linspace((-5,-.4,-1.3), (3, 1.4, -1.2), 10)
+    )
+
+    F0,T0 = getFT(cylseg, dip, pivot=(0,0,0))
+
+    for meshing,err in zip([20, 360], [1e-1, 1e-2]):
+        cylseg.meshing = meshing
+        F1,T1 = getFT(dip, cylseg, pivot=(0,0,0))
 
+        errF = np.max(np.linalg.norm(F1 + F0, axis=1) / np.linalg.norm(F1 - F0, axis=1))
+        print(errF)
 
 
     # import sys

diff --git a/src/magpylib/_src/obj_classes/class_magnet_CylinderSegment.py b/src/magpylib/_src/obj_classes/class_magnet_CylinderSegment.py
@@ -180,10 +180,7 @@ def _generate_mesh(self):
         """Generate mesh for force computation."""
         # Tests in getFT ensure that meshing, dimension and excitation are set
         r1, r2, h, phi1, phi2 = self.dimension
-        mesh, volumes = target_mesh_cylinder(r1, r2, h, phi1, phi2, self.meshing)
-        mesh = self.orientation.apply(mesh) + self.position
-        moments = volumes[:, np.newaxis] * self.orientation.apply(self.magnetization)
-        return mesh, moments
+        return target_mesh_cylinder(r1, r2, h, phi1, phi2, self.meshing, self.magnetization)
 
     # Static methods
     @staticmethod