CHRISPELL_FREEFEM++
Chrispell and Howell FreeFem++ Examples

CHRISPELL_FREEFEM++, examples which associated with a presentation on FreeFem++ by John Chrispell and Jason Howell.

Local information:

FreeFem++ is installed on the hallway machines, and can be accessed by typing:

        /usr/local/bin/FreeFem++
      

Licensing:

The computer code and data files made available on this web page are distributed under the GNU LGPL license.

Related Data and Programs:

BAMG, examples which illustrate the use of BAMG, a program for generating 2D meshes that can be used to define the geometry for the the finite element package FREEFEM++.

FREEFEM++, examples which illustrate the use of the FREEFEM++ package, a high-level integrated development environment for the numerical solution of nonlinear multiphysics partial differential equations (PDE's) in 2D and 3D.

FREEFEM++_MSH, a data directory which contains examples of the mesh files created by the FreeFem++ program, which use the extension ".msh".

FREEFEM++_MSH_IO, a FORTRAN90 library which can read and write files used by the FreeFem++ finite element program to store mesh information.

HECHT_FREEFEM++ examples which accompanied the standard reference paper for FREEFEM++, used by Frederic Hecht to illustrate special features of the program.

MITCHELL_FREEFEM++, examples which illustrate the implementation of the Mitchell 2D elliptic partial differential equation (PDE) test problems using FREEFEM++.

Reference:

1. John Chrispell, Jason Howell,
   Finite Element Approximation of Partial Differential Equations Using FreeFem++, or, How I Learned to Stop Worrying and Love Numerical Analysis.
2. Frederic Hecht,
   New development in FreeFem++,
   Journal of Numerical Mathematics,
   Volume 20, Number 3-4, 2012, pages 251-265.

Examples and Tests:

ADAPTMESH demonstrates how a mesh can be adapted corresponding to some function.

• adaptmesh.edp, the input file.
• adaptmesh_0.ps
• adaptmesh_0.png
• adaptmesh_1.ps
• adaptmesh_1.png
• adaptmesh_2.ps
• adaptmesh_2.png
• adaptmesh_3.ps
• adaptmesh_3.png

CAVITY sets up and solves the Stokes flow equations for the driven cavity problem.

• cavity.edp, the input file.
• cavity.ps
• cavity.png

COMMAND shows how FreeFem++ can accept user input from the commandline.

• command.edp, the input file.

FLOW_MESH demonstrates how a mesh can be created by specifying a sequence of lines that form the boundary.

• flow_mesh.edp, the input file.
• flow_mesh.ps
• flow_mesh.png

IO demonstrates how FreeFem++ can read arrays from a file, or write them to a file. Note a peculiarity: a file containing a vector of data must have an initial line listing the number of data items.

• io.edp, the input file.
• input.txt, a file to be read.
• output.txt, a file to be written.

NS_CAVITY sets up and solves the Navier-Stokes flow equations for the driven cavity problem.

• ns_cavity.edp, the input file.
• ns_cavity.ps
• ns_cavity.png

POISSON sets up and solves a Poisson problem in a square.

• poisson.edp, the input file.
• poisson.ps
• poisson.png

SCRIPTING shows how the EXEC command can be used to run system commands during FreeFem++'s execution. In this case, FreeFem++ writes out a file containing data, and then issues an EXEC command that asks gnuplot to display a plot of the data.

• scripting.edp, the input file.
• poisson10.txt, a table of solution values on a regular (X,Y) grid.
• poisson10.eps, a plot of the data, created by an EXEC call to GNUPLOT.
• poisson10.png, a PNG version.

SQUARE_MESH is a very simple example that creates and plots a square mesh. Two variations have been added.

• square_mesh.edp, the input file.
• square_mesh01.ps
• square_mesh01.png
• square_mesh02.ps
• square_mesh02.png
• square_mesh03.ps
• square_mesh03.png

You can go up one level to the Examples directory.