GetDP is a rather general open source finite element solver using mixed elements to discretize de Rham-type complexes in one, two and three dimensions. GetDP is developed by the ACE group from the Montefiore Institute at the University of Liège, and is released under the GNU GPL.

Getting started

ONELAB allows to use GetDP as a black-box solver: you don't need to know anything about finite elements or de Rham complexes in order to run your first simulations:

Download and uncompress the Gmsh/GetDP bundle for Windows64, Windows32, Linux64, Linux32 or MacOSX. (If you prefer you can of course also download and install Gmsh and GetDP independently.)
Double-click on the Gmsh executable (gmsh.exe
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on Windows).
Load one of the GetDP models (.pro file) through the File/Open menu, e.g. magnet.pro for the Template:GetDPFile example.
Click on Run.
... that's it!

Magnet-1.png

Launch Gmsh and load the GetDP model magnet.pro with the File/Open menu.
Magnet-2.png

Click on Run to launch a computation. You can change any parameter and then Run again!

Featured GetDP models

Electric Machines
Electromechanical Relay
Magnetodynamics with cohomology conditions
Multiple scattering with Sommerfeld ABC and with Perfectly Matched Layer (PML)
Time reversal in free space

All GetDP models

Category:GetDP

How does it work?

ONELAB numeric parameters can be defined directly in the input files through the DefineConstant syntax:

DefineConstant[ x = 1 ];
DefineConstant[ x = {1, Label "My variable"} ];
DefineConstant[ x = {1, Label "My variable", Choices {0,1}} ];
DefineConstant[ x = {1, Label "My variable", Choices {0,3,5}} ];
DefineConstant[ x = {1, Label "My variable", Choices {0="Zero",3="Three", 5="Five"}} ];
DefineConstant[ x = {1, Label "My variable", Min 0, Max 50, Step 5} ]
DefineConstant[ x = {1, Label "My variable", Min 0, Max 50, Step 5, Path "Variables/input/"} ];

When the input file is analyzed, if the parameter has not been previously defined, it takes the value provided in DefineConstant and is sent to the ONELAB server. If the input file is re-analyzed later, the value will be updated using the value from the server (unless it is labeled ReadOnly: see below). The same syntax can be used to define string parameters:

DefineConstant[ s = "a" ];
DefineConstant[ s = {"a", Label "My string variable"} ];
DefineConstant[ s = {"a", Label "My string variable", Choices {"a", "b", "c"} } ];
DefineConstant[ x = {"a", Label "My string variable", Kind "File"} ]
DefineConstant[ x = {"a", Label "My variable", Path "Variables/Input/"} ];

Common parameter attributes

Here's the list of attributes available for all ONELAB parameters:

Label string: User-friendly label used in the graphical user interface
Path: Full path of the parameter in the ONELAB server (represented as a tree in the graphical user interface)
ReadOnly 0|1: If ReadOnly is set, the value cannot be changed server-side, and the value provided in DefineConstant is always used
Highlight color_string: Color used to draw the widget in the graphical interface
Visible 0|1: Should the parameter be visible in the interface?
Closed 0|1: Should the subtree containing this variable be closed?
Help string: Help string for this parameter
AutoCheck 0|1: Allows to disable automatic "check" (rebuild of the interface) when the value is changed
GmshOption string: Treat the parameter as the name of a Gmsh option (e.g. Mesh.Algorithm)

Number attributes

In addition, numbers can take the following specific attributes:

Min number: Minimum value allowed when scrolling in the interface, and when looping on the parameter
Max number: Maximum value allowed when scrolling in the interface, and when looping on the parameter
Step number: Step value used when scrolling in the interface, and when looping on the parameter
Range {min, max, step}: Alternate syntax for Min, Max and Step
Choices{number, number, ...}: Possible choices for the parameter
Choices{number=string, number=string, ...}: Possible choices for the parameter, with string labels for each choice
ReadOnlyRange 0|1: Treat the range (or the choices, if they are provided) as read-only
Loop string: Loop over the parameter (the string indicates the loop imbrication level: currently "1", "2" or "3")
Graph string

String attributes

String accepts the following specific attributes:

Kind string: Mutable kind of the string (currently: "file")
Choices {string, string, ...}: Possible choices for the parameter
MultipleSelection 0|1: Allow multiple selection in choices
Macro string: Treat the parameter as the filename of a macro that will be run when the parameter is clicked in the interface

GetDP

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