pymor.analyticalproblems package

Submodules

burgers module

pymor.analyticalproblems.burgers.burgers_problem(v=1.0, circle=True, initial_data_type='sin', parameter_range=(1.0, 2.0))[source]

One-dimensional Burgers-type problem.

The problem is to solve

∂_t u(x, t, μ)  +  ∂_x (v * u(x, t, μ)^μ) = 0
                               u(x, 0, μ) = u_0(x)

for u with t in [0, 0.3] and x in [0, 2].

Parameters

v
The velocity v.
circle
If True, impose periodic boundary conditions. Otherwise Dirichlet left, outflow right.
initial_data_type
Type of initial data ('sin' or 'bump').
parameter_range
The interval in which μ is allowed to vary.
pymor.analyticalproblems.burgers.burgers_problem_2d(vx=1.0, vy=1.0, torus=True, initial_data_type='sin', parameter_range=(1.0, 2.0))[source]

Two-dimensional Burgers-type problem.

The problem is to solve

∂_t u(x, t, μ)  +  ∇ ⋅ (v * u(x, t, μ)^μ) = 0
                               u(x, 0, μ) = u_0(x)

for u with t in [0, 0.3], x in [0, 2] x [0, 1].

Parameters

vx
The x component of the velocity vector v.
vy
The y component of the velocity vector v.
torus
If True, impose periodic boundary conditions. Otherwise, Dirichlet left and bottom, outflow top and right.
initial_data_type
Type of initial data ('sin' or 'bump').
parameter_range
The interval in which μ is allowed to vary.

elliptic module

class pymor.analyticalproblems.elliptic.StationaryProblem(domain, rhs=None, diffusion=None, advection=None, nonlinear_advection=None, nonlinear_advection_derivative=None, reaction=None, nonlinear_reaction=None, nonlinear_reaction_derivative=None, dirichlet_data=None, neumann_data=None, robin_data=None, parameter_space=None, name=None)[source]

Bases: pymor.core.interfaces.ImmutableInterface

Linear elliptic problem description.

The problem consists in solving

- ∇ ⋅ [d(x, μ) ∇ u(x, μ)] + ∇ ⋅ [f(x, u(x, μ), μ)] + c(x, u(x, μ), μ) = f(x, μ)

for u.

Parameters

domain
A DomainDescription of the domain the problem is posed on.
rhs
The Function f(x, μ). rhs.dim_domain has to agree with the dimension of domain, whereas rhs.shape_range has to be ().
diffusion
The Function d(x, μ) with shape_range of either () or (dim domain, dim domain).
advection
The Function f, only depending on x, with shape_range of (dim domain,).
nonlinear_advection
The Function f, only depending on u, with shape_range of (dim domain,).
nonlinear_advection_derivative
The derivative of f, only depending on u, with respect to u.
reaction
The Function c, only depending on x, with shape_range of ().
nonlinear_reaction
The Function c, only depending on u, with shape_range of ().
nonlinear_reaction_derivative
The derivative of the Function c, only depending on u, with shape_range of ().
dirichlet_data
Function providing the Dirichlet boundary values.
neumann_data
Function providing the Neumann boundary values.
robin_data
Tuple of two Functions providing the Robin parameter and boundary values.
parameter_space
ParameterSpace for the problem.
name
Name of the problem.

Methods

ImmutableInterface generate_sid, with_, __setattr__
BasicInterface disable_logging, enable_logging, has_interface_name, implementor_names, implementors

Attributes

StationaryProblem advection, diffusion, dirichlet_data, domain, neumann_data, nonlinear_advection, nonlinear_advection_derivative, nonlinear_reaction, nonlinear_reaction_derivative, reaction, rhs, robin_data
ImmutableInterface add_with_arguments, sid, sid_ignore, with_arguments
BasicInterface logger, logging_disabled, name, uid
domain
rhs
diffusion
advection
nonlinear_advection
nonlinear_advection_derivative
reaction
nonlinear_reaction
nonlinear_reaction_derivative
dirichlet_data
neumann_data
robin_data

helmholtz module

pymor.analyticalproblems.helmholtz.helmholtz_problem(domain=RectDomain([[0 0], [1 1]]), rhs=None, parameter_range=(0.0, 100.0), dirichlet_data=None, neumann_data=None)[source]

Helmholtz equation problem.

This problem is to solve the Helmholtz equation

- ∆ u(x, k) - k^2 u(x, k) = f(x, k)

on a given domain.

Parameters

domain
A DomainDescription of the domain the problem is posed on.
rhs
The Function f(x, μ).
parameter_range
A tuple (k_min, k_max) describing the interval in which k is allowd to vary.
dirichlet_data
Function providing the Dirichlet boundary values.
neumann_data
Function providing the Neumann boundary values.

instationary module

class pymor.analyticalproblems.instationary.InstationaryProblem(stationary_part, initial_data, T=1.0, parameter_space=None, name=None)[source]

Bases: pymor.core.interfaces.ImmutableInterface

Instationary problem description.

This class desciribes an instationary problem of the form

|    ∂_t u(x, t, μ) + A(u(x, t, μ), t, μ) = f(x, t, μ),
|                              u(x, 0, μ) = u_0(x, μ)

where A, f are given by the problem’s stationary_part and t is allowed to vary in the interval [0, T].

Parameters

stationary_part
The stationary part of the problem.
initial_data
Function providing the initial values u_0.
T
The final time T.
parameter_space
ParameterSpace for the problem.
name
Name of the problem.

Methods

InstationaryProblem with_
ImmutableInterface generate_sid, __setattr__
BasicInterface disable_logging, enable_logging, has_interface_name, implementor_names, implementors

Attributes

InstationaryProblem parameter_space, stationary_part, T, with_arguments
ImmutableInterface add_with_arguments, sid, sid_ignore
BasicInterface logger, logging_disabled, name, uid
T
stationary_part
parameter_space
name

thermalblock module

pymor.analyticalproblems.thermalblock.thermal_block_problem(num_blocks=(3, 3), parameter_range=(0.1, 1))[source]

Analytical description of a 2D ‘thermal block’ diffusion problem.

This problem is to solve the elliptic equation

- ∇ ⋅ [ d(x, μ) ∇ u(x, μ) ] = f(x, μ)

on the domain [0,1]^2 with Dirichlet zero boundary values. The domain is partitioned into nx x ny blocks and the diffusion function d(x, μ) is constant on each such block (i,j) with value μ_ij.

----------------------------
|        |        |        |
|  μ_11  |  μ_12  |  μ_13  |
|        |        |        |
|---------------------------
|        |        |        |
|  μ_21  |  μ_22  |  μ_23  |
|        |        |        |
----------------------------

Parameters

num_blocks
The tuple (nx, ny)
parameter_range
A tuple (μ_min, μ_max). Each Parameter component μ_ij is allowed to lie in the interval [μ_min, μ_max].