SciGetFem >> SciGetFem
SciGetFem
- getfem types — Types reference
- gf_asm — General assembly function.
Many of the functions below use more than one mesh_fem: the main
mesh_fem (mf_u) used for the main unknown, and data mesh_fem (mf_d)
used for the data. It is always assumed that the Qdim of mf_d is
equal to 1: if mf_d is used to describe vector or tensor data, you
just have to "stack" (in fortran ordering) as many scalar fields as
necessary.
- gf_asm_pdetoolbc — 'pdetool style' assembling of boundary conditions
- gf_colormap — Return a colormap, or change the current colormap
- gf_compute — Various computations involving the solution U to a finite element problem.
- gf_compute_Q1grid_interp — see the help page of gf_compute
- gf_cont_struct — This object serves for storing parameters and data used in numerical
continuation of solution branches of models (for more details about
continuation see the GetFEM++ user documentation).
- gf_cont_struct_get — General function for querying information about cont_struct objects and for
applying them to numerical continuation.
- gf_cvstruct_get — General function for querying information about convex_structure objects.
The convex structures are internal structures of getfem++. They do not
contain points positions. These structures are recursive, since the faces
of a convex structures are convex structures.
- gf_delete — Delete an existing getfem object from memory (mesh, mesh_fem, etc.).
SEE ALSO:
gf_workspace, gf_mesh, gf_mesh_fem.
- gf_eltm — This object represents a type of elementary matrix. In order to obtain a
numerical value of these matrices, see gf_mesh_im_get(mesh_im MI, 'eltm').
If you have very particular assembling needs, or if you just want to check
the content of an elementary matrix, this function might be useful. But
the generic assembly abilities of gf_asm(...) should suit most needs.
- gf_fem — This object represents a finite element method on a reference element.
- gf_fem_get — General function for querying information about FEM objects.
- gf_geotrans — The geometric transformation must be used when you are building a custom
mesh convex by convex (see the add_convex() function of mesh): it also
defines the kind of convex (triangle, hexahedron, prism, etc..)
- gf_geotrans_get — General function for querying information about geometric transformations
objects.
- gf_global_function — Global function object is represented by three functions:
* The function
val
.
* The function gradient grad
.
* The function Hessian hess
.
this type of function is used as local and global enrichment function. The
global function Hessian is an optional parameter (only for fourth order
derivative problems).
- gf_global_function_get — General function for querying information about global_function objects.
- gf_integ — General object for obtaining handles to various integrations methods on
convexes (used when the elementary matrices are built).
- gf_integ_get — General function for querying information about integration method objects.
- gf_interpolated_on_grid — interpolates a field defined on mesh_fem 'mf' on a cartesian
grid [X(1),X(2),...] x [Y(1),Y(2),...] x ...
- gf_levelset — The level-set object is represented by a primary level-set and optionally
a secondary level-set used to represent fractures (if p(x) is the primary
level-set function and s(x) is the secondary level-set, the crack is
defined by
and
: the role of the secondary is to determine
the crack front/tip).
note:
All tools listed below need the package qhull installed on your
system. This package is widely available. It computes convex hull and
delaunay triangulations in arbitrary dimension.
- gf_levelset_get — General function for querying information about LEVELSET objects.
- gf_levelset_set — General function for modification of LEVELSET objects.
- gf_linsolve — Various linear system solvers.
- gf_mesh — This object is able to store any element in any dimension even if you mix
elements with different dimensions.
- gf_mesh_fem — This object represents a finite element method defined on a whole mesh.
- gf_mesh_fem_get — General function for inquiry about mesh_fem objects.
- gf_mesh_fem_get_eval — see the help of gf_mesh_fem_get(mf,'eval')
- gf_mesh_fem_set — General function for modifying mesh_fem objects.
- gf_mesh_get — General mesh inquiry function. All these functions accept also a
mesh_fem argument instead of a mesh M (in that case, the mesh_fem
linked mesh will be used).
- gf_mesh_im — This object represents an integration method defined on a whole mesh (an
potentialy on its boundaries).
- gf_mesh_im_data — This object represents data defined on a mesh_im object.
- gf_mesh_im_data_get — General function extracting information from mesh_im_data objects.
- gf_mesh_im_data_set — General function for modifying mesh_im objects
- gf_mesh_im_get — General function extracting information from mesh_im objects.
- gf_mesh_im_set — General function for modifying mesh_im objects
- gf_mesh_levelset — General constructor for mesh_levelset objects. The role of this object is
to provide a mesh cut by a certain number of level_set. This object is
used to build conformal integration method (object mim and enriched finite
element methods (Xfem)).
- gf_mesh_levelset_get — General function for querying information about mesh_levelset objects.
- gf_mesh_levelset_set — General function for modification of mesh_levelset objects.
- gf_mesh_set — General function for modification of a mesh object.
- gf_mesher_object — This object represents a geometric object to be meshed by the (very)
experimental meshing procedure of Getfem.
- gf_mesher_object_get — General function for querying information about mesher_object objects.
- gf_model — model variables store the variables and the state data and the
description of a model. This includes the global tangent matrix, the right
hand side and the constraints. There are two kinds of models, the
real
and the complex
models.
model object is the evolution for getfem++ 4.0 of the mdstate object.
- gf_model_get — Get information from a model object.
- gf_model_set — Modifies a model object.
- gf_multi_contact_frame — This object serves for describing a multi-contact situation between
potentially several deformable bodies and eventually some rigid obstacles.
(for more details see the GetFEM++ user documentation).
- gf_multi_contact_frame_get — General function for querying information about multi contact frame objects.
- gf_multi_contact_frame_set — General function for modification of multi_contact_frame objects.
- gf_plot — This function plots a 2D or 3D finite elements
field.
- gf_plot_1D — This function plots a 1D finite element field.
- gf_plot_mesh — General mesh plotting function.
- gf_plot_slice — this function is used to plot a slice of
mesh/mesh_fem
- gf_poly — Performs various operations on the polynom POLY.
- gf_precond — The preconditioners may store REAL or COMPLEX values. They accept getfem
sparse matrices and Matlab sparse matrices.
- gf_precond_get — General function for querying information about precond objects.
- gf_slice — Creation of a mesh slice. Mesh slices are very similar to a
P1-discontinuous mesh_fem on which interpolation is very fast. The slice is
built from a mesh object, and a description of the slicing operation, for
example::
sl = gf_slice({'planar',+1,[0;0],[1;0]}, m, 5);
cuts the original mesh with the half space {y>0}. Each convex of the
original mesh
m
is simplexified (for example a quadrangle is splitted
into 2 triangles), and each simplex is refined 5 times.
Slicing operations can be:
* cutting with a plane, a sphere or a cylinder
* intersection or union of slices
* isovalues surfaces/volumes
* "points", "streamlines" (see below)
If the first argument is a mesh_fem mf
instead of a mesh, and if it is
followed by a mf
-field u
, then the deformation u
will be applied to the
mesh before the slicing operation.
The first argument can also be a slice.
- gf_slice_get — General function for querying information about slice objects.
- gf_slice_set — Edition of mesh slices.
- gf_solve — General solver for getfem PDE
- gf_spmat — Create a new sparse matrix in getfem++ format. These sparse matrix can be stored as CSC (compressed column
sparse), which is the format used by Matlab, or they can be stored as WSC
(internal format to getfem). The CSC matrices are not writable (it would
be very inefficient), but they are optimized for multiplication with
vectors, and memory usage. The WSC are writable, they are very fast with
respect to random read/write operation. However their memory overhead is
higher than CSC matrices, and they are a little bit slower for
matrix-vector multiplications.
By default, all newly created matrices are build as WSC matrices. This can
be changed later with
gf_spmat_set(spmat S, 'to_csc',...)
, or may be changed
automatically by getfem (for example
gf_linsolve()
converts the
matrices to CSC).
The matrices may store REAL or COMPLEX values.
- gf_spmat_get —
- gf_spmat_set — Modification of the content of a getfem sparse matrix.
- gf_typeof — Get the type of a GetFEM object.
- gf_undelete — Undelete an existing getfem object from memory (mesh, mesh_fem, etc.).
SEE ALSO:
gf_workspace, gf_delete.
- gf_util — Performs various operations which do not fit elsewhere.
- gf_workspace — Getfem workspace management function.
Getfem uses its own workspaces in Matlab, independently of the
matlab workspaces (this is due to some limitations in the memory
management of matlab objects). By default, all getfem variables
belong to the root getfem workspace. A function can create its own
workspace by invoking gf_workspace('push') at its beginning. When
exiting, this function MUST invoke gf_workspace('pop') (you can
use matlab exceptions handling to do this cleanly when the
function exits on an error).
- Objects — This is a description of the objects found in GetFEM.
- preliminary — This is just a short summary of the terms employed in this
manual.
- Examples
- Another Laplacian with exact solution — This is the scilab/demos/demo_laplacian.sce example.
- Avoiding the bricks framework — This is a description on how to avoid the bricks
framework.
- Linear and non-linear elasticity — This example uses a mesh that was generated with GiD.
- A step by step basic example — This example shows the basic usage of getfem.
- Sparse functions
- sp_cgs — Use a conjugate gradient for a normal equation to solve the system A.x = b
- sp_cgs — Use a conjugate gradient to solve the system A.x = b
- sp_lu — Performs a Cholesky decomposition on a sparse matrix
- sp_lu — Performs an incomplete Cholesky decomposition on a sparse matrix
- sp_cgs — Use a Cholesky decomposition to solve the system A.x = b
- sp_cgs — Use a generalized minimum residual algorithm of Saad &
Schultz to solve the system A.x = b
- sp_lu — Performs a LU decomposition on a sparse matrix
- sp_lu — Performs an incomplete LU decomposition on a sparse matrix
- sp_cgs — Use a LU decomposition to solve the system A.x = b
- sp_cgs — Use a modified generalized conjugate residual algorithm to solve the system A.x = b