# diffusion/poisson_iga.py¶

Description

Poisson equation solved in a single patch NURBS domain using the isogeometric analysis (IGA) approach.

Find such that:

Try setting the Dirichlet boundary condition (ebcs) on various sides of the domain ('Gamma1', …, 'Gamma4').

View the results using:

$./resview.py patch2d.vtk -f t:wt:f0.4 1:vw  source code r""" Poisson equation solved in a single patch NURBS domain using the isogeometric analysis (IGA) approach. Find :math:t such that: .. math:: \int_{\Omega} c \nabla s \cdot \nabla t = \int_{\Omega_0} f s \;, \quad \forall s \;. Try setting the Dirichlet boundary condition (ebcs) on various sides of the domain ('Gamma1', ..., 'Gamma4'). View the results using::$ ./resview.py patch2d.vtk -f t:wt:f0.4 1:vw
"""
from __future__ import absolute_import
from sfepy import data_dir

filename_domain = data_dir + '/meshes/iga/patch2d.iga'

materials = {
'm' : ({'c' : 1.0, 'f' : -10.0},),
}

regions = {
'Omega' : 'all',
'Omega_0' : 'vertices in (x > 1.5)',
'Gamma1' : ('vertices of set xi00', 'facet'),
'Gamma2' : ('vertices of set xi01', 'facet'),
'Gamma3' : ('vertices of set xi10', 'facet'),
'Gamma4' : ('vertices of set xi11', 'facet'),
}

fields = {
'temperature' : ('real', 1, 'Omega', None, 'H1', 'iga'),
}

variables = {
't' : ('unknown field', 'temperature', 0),
's' : ('test field',    'temperature', 't'),
}

ebcs = {
't1' : ('Gamma3', {'t.0' : 2.0}),
't2' : ('Gamma4', {'t.0' : -2.0}),
}

integrals = {
'i' : 3,
}

equations = {
'Temperature' : """dw_laplace.i.Omega(m.c, s, t)
= dw_volume_lvf.i.Omega_0(m.f, s)"""
}

solvers = {
'ls' : ('ls.scipy_direct', {}),
'newton' : ('nls.newton', {
'i_max'      : 1,
'eps_a'      : 1e-10,
}),
}

options = {
'nls' : 'newton',
'ls' : 'ls',
}