GetDP

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:

1. 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.)
2. Double-click on the Gmsh executable (gmsh.exe
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   on Windows).
3. Load one of the GetDP models (.pro file) through the File/Open menu, e.g. inductor.pro for the simple inductor/core example.
4. Click on Run.
5. ... that's it!

• 

  Launch Gmsh and load the GetDP model magnet.pro with the File/Open menu.

• GmshGetDP 2.png

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

Featured GetDP models

• Simple inductor/core system
• Rotating 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: <syntaxhighlight lang="cpp"> 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/"} ]; </syntaxhighlight>

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: <syntaxhighlight lang="cpp"> 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/"} ]; </syntaxhighlight>

Note that when the code is run without the ONELAB server, the parameters take the default values provided by DefineConstant.

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 string

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 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