Added and updtd examples for long particle

Author: davidcortesortuno

examples/neb_micromagnetic/elongated_particle/elongated_particle_along_z.py

@@ -1,4 +1,3 @@
-from __future__ import print_function
 import pytest
 
 """
@@ -46,7 +45,6 @@
 from fidimag.common import CuboidMesh
 from fidimag.micro import UniformExchange, UniaxialAnisotropy, Demag
 from fidimag.common.nebm_geodesic import NEBM_Geodesic
-from fidimag.common.nebm_cartesian import NEBM_Cartesian
 import numpy as np
 
 # Material Parameters ---------------------------------------------------------
@@ -78,7 +76,7 @@ def relax_neb(sim, k, maxst, simname, initial_images, interpolations,
                             'linear' or 'rotation' (Rodrigues formulae)
     """
 
-    method_dict = {'Cartesian': NEBM_Cartesian, 'Geodesic': NEBM_Geodesic}
+    method_dict = {'Geodesic': NEBM_Geodesic}
 
     neb = method_dict[method](sim,
                               initial_images,
@@ -139,7 +137,7 @@ def test_energy_barrier_cylinder():
     init_im = [(0, 0, -1), (0, 0.9, 0.1), (0, 0, 1)]
     interp = [8, 8]
 
-    for method in ['Geodesic', 'Cartesian']:
+    for method in ['Geodesic']:
         relax_neb(elongated_part_sim(),
                   1e4, 2000,
                   'neb_cylinder_z-axis_{}'.format(method),

examples/neb_micromagnetic/elongated_particle/elongated_particle_along_z_FS.py

@@ -0,0 +1,83 @@
+# FIDIMAG:
+from fidimag.micro import Sim
+from fidimag.common import CuboidMesh
+from fidimag.micro import UniformExchange, UniaxialAnisotropy, Demag
+from fidimag.common.nebm_FS import NEBM_FS
+import numpy as np
+import logging
+import matplotlib.pyplot as plt
+
+# Material Parameters ---------------------------------------------------------
+
+A = 10e-12
+Kx = 3e5
+Ms = 3.98e5
+
+# Mesh ------------------------------------------------------------------------
+
+# Define an elongated cylinder along the y direction
+def cylinder(r, centre, radius):
+    if (r[0] - centre[0]) ** 2. + (r[1] - centre[1]) ** 2 <= radius ** 2.:
+        return Ms
+    else:
+        return 0
+
+# Finite differences mesh
+mesh = CuboidMesh(nx=6, ny=6, nz=35,
+                  dx=2, dy=2, dz=2,
+                  unit_length=1e-9)
+
+centre = (np.max(mesh.coordinates[:, 0]) * 0.5,
+          np.max(mesh.coordinates[:, 1]) * 0.5)
+
+
+# Prepare simulation ----------------------------------------------------------
+
+def elongated_part_sim():
+    sim = Sim(mesh)
+    sim.Ms = lambda r: cylinder(r, centre, 8)
+    sim.add(UniformExchange(A=A))
+    sim.add(UniaxialAnisotropy(Kx, axis=(0, 0, 1)))  # Anisotropy along y
+    sim.add(Demag())
+
+    return sim
+
+
+# -----------------------------------------------------------------------------
+
+init_im = [(0, 0, -1), (0, 0.9, 0.1), (0, 0, 1)]
+interp = [10, 10]
+
+sim = elongated_part_sim()
+nebm = NEBM_FS(sim, init_im, interpolations=interp, name='neb_cylinder_z-axis_FS',
+                interpolation_method='rotation', spring_constant=1e5)
+
+# dt = integrator.stepsize means after every integrator step, the images
+# are rescaled. We can run more integrator steps if we decrease the
+# stepsize, e.g. dt=1e-3 and integrator.stepsize=1e-4
+nebm.integrator.maxSteps = 10
+nebm.integrator.run_for(10,
+                        # save_vtks_every=save_every,
+                        # save_npys_every=save_every,
+                        )
+
+bandEnergies = np.loadtxt('neb_cylinder_z-axis_FS_energy.ndt')[:, 1:]
+bandDistances = np.loadtxt('neb_cylinder_z-axis_FS_dYs.ndt')[:, 1:]
+
+# Get the Matplotlib logger
+mpl_logger = logging.getLogger('matplotlib')
+# Set the logging level to 'WARNING' or higher
+mpl_logger.setLevel(logging.WARNING)
+pil_logger = logging.getLogger('PIL')
+pil_logger.setLevel(logging.WARNING)
+
+f, ax  = plt.subplots()
+print(bandDistances[1])
+dist = [1] + list(np.cumsum(bandDistances[1]))
+ax.plot(dist, bandEnergies[0], 'o--')
+
+st = -1
+dist = [0] + list(np.cumsum(bandDistances[st]))
+ax.plot(dist, bandEnergies[st], 'o-')
+plt.show()
+