simfempy 2.0.26

A small package for fem

SIMple Finite Element Methods in PYthon

import matplotlib.pyplot as plt
import matplotlib.gridspec as gridspec
import pygmsh
from simfempy.applications.heat import Heat
from simfempy.applications.problemdata import ProblemData
from simfempy.meshes.simplexmesh import SimplexMesh
from simfempy.meshes import plotmesh, animdata

# create mesh
h=0.1
with pygmsh.geo.Geometry() as geom:
    holes = []
    rectangle = geom.add_rectangle(xmin=-1.5, xmax=-0.5, ymin=-1.5, ymax=-0.5, z=0, mesh_size=h)
    geom.add_physical(rectangle.surface, label="200")
    geom.add_physical(rectangle.lines, label="20")  # required for correct boundary labels (!?)
    holes.append(rectangle)
    circle = geom.add_circle(x0=[0, 0], radius=0.5, mesh_size=h, num_sections=6, make_surface=False)
    geom.add_physical(circle.curve_loop.curves, label="3000")
    holes.append(circle)
    p = geom.add_rectangle(xmin=-2, xmax=2, ymin=-2, ymax=2, z=0, mesh_size=h, holes=holes)
    geom.add_physical(p.surface, label="100")
    for i in range(len(p.lines)): geom.add_physical(p.lines[i], label=f"{1000 + i}")
    mesh = geom.generate_mesh()
mesh = SimplexMesh(mesh=mesh)
# create problem data
data = ProblemData()
# boundary conditions
data.bdrycond.set("Dirichlet", [1000, 3000])
data.bdrycond.set("Neumann", [1001, 1002, 1003])
data.bdrycond.fct[1000] = lambda x, y, z: 200
data.bdrycond.fct[3000] = lambda x, y, z: 320
# postprocess
data.postproc.set(name='bdrymean_right', type='bdry_mean', colors=1001)
data.postproc.set(name='bdrymean_left', type='bdry_mean', colors=1003)
data.postproc.set(name='bdrymean_up', type='bdry_mean', colors=1002)
data.postproc.set(name='bdrynflux', type='bdry_nflux', colors=[3000])
# paramaters in equation
data.params.set_scal_cells("kheat", [100], 0.001)
data.params.set_scal_cells("kheat", [200], 10.0)
data.params.fct_glob["convection"] = ["0", "0.001"]
# create application
heat = Heat(mesh=mesh, problemdata=data, fem='p1')
static = True
if static:
    # run static
    result = heat.static()
    print(f"{result=}")
    # for p, v in result.data['global'].items(): print(f"{p}: {v}")
    fig = plt.figure(figsize=(10, 8))
    fig.suptitle("Heat static", fontsize=16)
    outer = gridspec.GridSpec(1, 2, wspace=0.2, hspace=0.2)
    plotmesh.meshWithBoundaries(heat.mesh, fig=fig, outer=outer[0])
    result.data.update({'cell': {'k': heat.kheatcell}})
    plotmesh.meshWithData(heat.mesh, data=result.data, alpha=0.5, fig=fig, outer=outer[1])
    plt.show()
else:
    # run dynamic
    data.params.fct_glob["initial_condition"] = "200"
    t_final, dt, nframes = 2500, 10, 50
    result = heat.dynamic(heat.initialCondition(), t_span=(0, t_final), nframes=nframes, dt=dt)
    # print(f"{result=}")
    nhalf = int(nframes/2)
    u = result.data['point']['U']
    fig = plt.figure(figsize=(10, 8))
    fig.suptitle("Heat dynamic", fontsize=16)
    outer = gridspec.GridSpec(1, 3, wspace=0.2, hspace=0.2)
    plotmesh.meshWithData(heat.mesh, title=f't={result.time[0]}', point_data={'u': u[0]}, fig=fig, outer=outer[0])
    plotmesh.meshWithData(heat.mesh, title=f't={result.time[nhalf]}', point_data={'u': u[nhalf]}, fig=fig, outer=outer[1])
    plotmesh.meshWithData(heat.mesh, title=f't={result.time[-1]}', point_data={'u': u[-1]}, fig=fig, outer=outer[2])
    plt.show()
    postprocs = result.data['global']
    for i,k in enumerate(postprocs):
        plt.plot(result.time, postprocs[k], label=k)
    plt.legend()
    plt.grid()
    plt.show()
    anim = animdata.AnimData(mesh, u)
    plt.show()