FEATool  v1.6
Finite Element Analysis Toolbox
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Graphical User Interface

This section describes how to use the FEATool GUI (available with Matlab or Octave version 4.0 or later). Please note that the GUI may look different depending on your system configuration and Octave or Matlab version running FEATool.

Main GUI Window

After launching FEATool in Octave or Matlab (by typing featool at the command prompt) the gui will load. The main gui window which will open is composed of the main gui axes, top menu and toolbar, left vertical mode and tool button bars, and also input, output, and terminal command windows. The function of these is explained below.


Main Gui Axes

The main gui axes is where the geometry, computational grid, and postprocessing results are displayed. The view can be controlled by the Zoom In , Zoom Out , Pan , and Rotate buttons in the top toolbar.


On the top of the gui toolbar there are menus for file, options, mode, and help operations. The function of these menus are described in detail below

The File menu features the following options:

  • New... clears the old problem data and opens the New Problem dialog box.
  • Open... allows for opening and loading a previously saved model (.fea file).
  • Save As... allows for saving the current state of a model (as a .fea file).
  • Save As M-Script Model... allows for saving the commands used in the session as a m-script model file (.m file). Note that m-script models does not save the grids or solutions, just the FEATool function calls that created them.
  • Clear M-Script Log Clears the m-script command log.
  • Import > Variables From Main Workspace... opens a dialog box which allows variables to be selected and imported from the Octave or Matlab workspace.
  • Export > Variables To Main Workspace... opens a dialog box which allows variables to be selected and exported to the main workspace.
  • Export > FEA Problem Struct To Main Workspace... exports the FEATool problem struct to the main workspace with the variable name fea.
  • Exit closes and exits the FEATool gui.

The Options menu firstly allows the axes and grid settings to be modified (these settings are described in the axes/grid settings section below). Additionally, the FEATool gui options can be inspected and edited by opening the Options... dialog box (this will effectively edit the guiparam.txt parameter file located in the featool/gui folder).

The Geometry menu allows for switching to Geometry Mode, adding specific points Add Point..., and also accessing the Combine Objects... option which allows specification of a complex formula for geometry object composition.

The Grid menu allows for switching to Grid Mode as well as accessing and specifying the Grid Generation Call.... Generate Quadrilateral Grid calls the structured quadrilateral grid generation routine (gridgen_quad). Convert Grid Cells converts between triangular and quadrilateral cells in 2D, and between tetrahedral and hexahedral cells in 3D. The Grid Smoothing menu option performs relaxed smoothing steps with either Laplacian or umbrella smoothing.

Grid Mode also supports import and export of grids through external ascii format files, these option can also be accessed from the Grid menu

In grid mode the overall global maximum grid cell size variable hmax can be changed from the Grid Size edit field in the grid tools toolbar.

The Equation and Boundary menus allows for switching to Equation/Boundary Modes and also opening the Equation/Boundary Settings... dialog boxes (see the equation and boundary mode sections). Moreover, the Model Constant and Expressions... option allows for input of modeling variables and expressions that can be used in equations and boundary settings, and postprocessing. Point sources and constraints can also be added here with the corresponding Add Point Sources... and Add Point Constraints... menu options.

The Solve menu similarly allows for switching to Solve Mode and also opening the Solver Settings... dialog box (these settings are described in the solver settings section). This menu also features an option to Get Initial Solution which computes the expressions defined in the equation settings Initial Condition fields and returns this as the solution. Moreover, the solver call command can be changed with the Solver Call Command... option.

The Post menu allows for switching to Postprocessing Mode, and opening the Postprocessing Settings... dialog box (see the postprocessing settings section below). In addition there are options for evaluating the minima and maxima for general expressions with Min/Max Evaluation..., points and line evaluation Point/Line Evaluation..., and integration of postprocessing expressions over subdomains Subdomain Integration... (calling intsubd) and boundaries Boundary Integration... (calling intbdr). The postprocessing call command can be inspected and changed with the Postprocessing Call... option. Moreover, the solution and postprocessing data can also be exported to be used with the General Mesh Viewer (GMV) through the Export Results... > GMV Format... menu option.

The Help menu opens the About... information dialog box and shows the FEATool license information. Moreover, there is also a link to open the FEATool Documentation.

Gui Toolbar

The top gui toolbar contains the following shortcut buttons (note that the GUI might show different options and icons depending on the Octave or Matlab version used)

  • New Problem starts a new problem definition
  • Open Problem loads a FEATool model
  • Save Problem saves the current FEATool model
  • Select allows for selection of cells in grid mode
  • Zoom In the main view axes
  • Zoom Out the main view axes
  • Pan around the main view axes
  • Rotate the main view axes (only in 3D)

Mode Buttons

To the left of the main view axes is the mode toolbar which consists of six mode buttons which switches between the different modes

  • Switches to geometry mode
  • Switches to grid generation mode
  • Switches to equation/subdomain specification mode (and opens the corresponding dialog box)
  • Switches to boundary settings mode (and opens the corresponding dialog box)
  • Switches to solve mode
  • Switches to postprocessing mode

Mode Tool Buttons

Below these buttons are the mode tool buttons which can change depending on which mode is selected.

Geometry Mode

  • Creates a square/rectangle
  • Creates a circle/ellipse
  • Creates a polygon
  • Creates a block
  • Creates a sphere
  • Creates a cylinder
  • Join selected geometry objects
  • Subtract geometry objects from first selected
  • Intersection of geometry objects
  • Split composite or transformed geometry object
  • Rotate, scale, and move selected geometry object
  • Delete selected geometry objects
  • Inspect/edit properties of selected geometry object

Grid Mode

  • Creates a line grid (only in 1D)
  • Initialize an unstructured grid
  • Uniform grid refinement
  • Select grid cells
  • Delete selected grid cells
  • Change subdomain number of selected grid cells
  • Change assignment of boundary numbering

Equation Mode

  • Open the equation/subdomain settings dialog box
  • Open the constants and expressions dialog box

Boundary Mode

  • Open the boundary settings dialog box

Solve Mode

  • Open solver settings dialog box
  • Solve problem with initial conditions prescribed from equation settings
  • Solve problem with last solution as initial value
  • Solve fluid flow problem with the FeatFlow external CFD solver

Post Mode

  • Open the postprocessing settings dialog box
  • Save and export the postprocessing plot to jpeg, png, or eps file
  • Export plot to the plotly web/cloud (requires a Plotly account and the Plotly Matlab API

Output and Message Window

Below the main gui axes is the output terminal window which displays messages, and output from the local FEATool workspace including output from the command input window below.

Command Input Window

On the bottom is the command input window which allows Matlab commands to be operated in the FEATool workspace (note that although the FEATool fea problem struct can be inspected and edited it might break and cause errors in the gui operation).

Axes/Grid Settings Dialog Box

In the Axis/Grid Settings dialog box the Grid on option turns on and off the grid. By having Axis equal checked the x and-axes will have equal proportional lengths. Bounding box indicates how much extra relative space should be shown apart from the geometry. Alternatively, one can manually set the Axis limits.


Keyboard Shortcuts

The following keyboard shortcuts are available in FEATool:

  • Ctrl + n Open the new problem dialog box to start a new model.
  • Ctrl + o Open a previously saved FEA problem model.
  • Ctrl + s Open Save FEA Model dialog box.
  • Ctrl + a Select all geometry objects in geometry mode, also works in list boxes and edit fields.
  • Ctrl + d Clear selected objects.

Moreover, in 2D Geometry mode one can hold down a Shift key while using the Create circle/ellipse tool to restrict to a circular geometry instead of allowing elliptical ones. In the FEATool Command Window prompt it is also possible to use the up and down arrow keys to scroll backwards and forwards through the command log history, and Ctrl + c to clear the command input edit field.