Learn more about Partial Differential Equation Toolbox

Using the pdetool Menus

On this page…
Introduction File Menu Edit Menu Options Menu Draw Menu Boundary Menu PDE Menu Mesh Menu Solve Menu Plot Menu Window Menu Help Menu

Introduction

The graphical user interface (GUI) has a pull-down menu bar that you can use to control the modeling. It conforms to common pull-down menu standards.

Menu items followed by a right arrow lead to a submenu. Menu items followed by an ellipsis lead to a dialog box. Stand-alone menu items lead to direct action. Some menu items can be executed by using keyboard accelerators.

pdetool also contains a toolbar with icon buttons for quick and easy access to some of the most important pdetool functions.

The following sections describe the contents of the pdetool menus and the dialog boxes associated with menu items.

Back to Top

File Menu

New	Create a new (empty) Constructive Solid Geometry (CSG) model.
Open	Load a model M-file from disk.
Save	Save the GUI session to a model M-file.
Save As	Save the GUI session to a new model M-file.
Print	Print a hardcopy of a figure.
Exit	Exit the pdetool graphical user interface.

New

New deletes the current CSG model and creates a new, empty model called "Untitled."

Open

Open displays a dialog box with a list of existing M-files from which you can select the file that you want to load. You can list the contents of a different folder by changing the path in the Selection text box. You can use the scroll bar to display more filenames. You can select a file by double-clicking the filename or by clicking the filename and then clicking the Done button. When you select a file, the CSG model that is stored in the model M-file is loaded into the workspace and displayed. Also, the equation, the boundary conditions, and information about the mesh and the solution are loaded if present, and the modeling and solution process continues to the same status as when you saved the file.

Save As

Save As displays a dialog box in which you can specify the name of the file in which to save the CSG model and other information regarding the GUI session. You can also change the folder in which it is saved. If the filename is given without a .m extension, .m is appended automatically.

The GUI session is stored in a model M-file, which contains a sequence of drawing commands and commands to recreate the modeling environment (axes scaling, grid, etc.). If you have already defined boundary conditions, PDE coefficients, created a triangular mesh, and solved the PDE, further commands to recreate the modeling and solution of the PDE problem are also included in the model M-file. The pdetool GUI can be started from the command line by entering the name of a model M-file. The model in the file is then directly loaded into the GUI.

Print

Print displays a dialog box for printing a hardcopy of a figure. Only the main part of the figure is printed, not the upper and lower menu and information parts. In the dialog box, you can enter any device option that is available for the MATLAB print command. The default device option is -dps (PostScript^® for black and white printers). The paper orientation can be set to portrait, landscape, or tall, and you can print to a printer or to file.

Back to Top

Edit Menu

Undo	Undo the last line when drawing a polygon.
Cut	Move the selected solid objects to the Clipboard.
Copy	Copy the selected objects to the Clipboard, leaving them intact in their original location.
Paste	Copy the contents of the Clipboard to the current CSG model.
Clear	Delete the selected objects.
Select All	Select all solid objects in the current CSG model. Also, select all outer boundaries or select all subdomains.

Paste

Paste displays a dialog box for pasting the contents of the Clipboard on to the current CSG model. The Clipboard contents can be repeatedly pasted adding a specified x- and y-axis displacement to the positions of the Clipboard objects.

Using the default values—zero displacement and one repetition—the Clipboard contents is inserted at its original position.

Back to Top

Options Menu

Grid	Turn grid on/off.
Grid Spacing	Adjust the grid spacing.
Snap	Turn the "snap-to-grid" feature on/off.
Axis Limits	Change the scaling of the drawing axes.
Axis Equal	Turn the "axis equal" feature on/off.
Turn off Toolbar Help	Turn off help texts for the toolbar buttons.
Zoom	Turn zoom feature on/off.
Application	Select application mode.
Refresh	Redisplay all graphical objects in the pdetool graphical user interface.

Grid Spacing

In the Grid Spacing dialog box, you can adjust the x-axis and y-axis grid spacing. By default, the MATLAB automatic linear grid spacing is used. If you turn off the Auto check box, the edit fields for linear spacing and extra ticks are enabled. For example, the default linear spacing -1.5:0.5:1.5 can be changed to -1.5:0.2:1.5. In addition, you can add extra ticks so that the grid can be customized to aid in drawing the desired 2-D domain. Extra tick entries can be separated using spaces, commas, semicolons, or brackets.

Examples:

pi
2/3, 0.78, 1.1
-0.123; pi/4

Clicking the Apply button applies the entered grid spacing; clicking the Done button ends the Grid Spacing dialog.

Axes Limits

In the Axes Limits dialog box, the range of the x-axis and the y-axis can be adjusted. The axis range should be entered as a 1-by-2 MATLAB vector such as [-10 10]. If you select the Auto check box, automatic scaling of the axis is used.

Clicking the Apply button applies the entered axis ranges; clicking the Close button ends the Axes Limits dialog.

Application

From the Application submenu, you can select from 10 available application modes. The application modes can also be selected using the pop-up menu in the upper right corner of the GUI.

The available application modes are:

• Generic Scalar (the default mode)

• Generic System

• Structural Mechanics — Plane Stress

• Structural Mechanics — Plane Strain

• Electrostatics

• Magnetostatics

• AC Power Electromagnetics

• Conductive Media DC

• Heat Transfer

• Diffusion

See Application Modes for more details.

Back to Top

Draw Menu

Draw Mode	Enter draw mode.
Rectangle/square	Draw a rectangle/square starting at a corner. Using the left mouse button, click-and-drag to create a rectangle. Using the right mouse button (or Ctrl+click), click-and-drag to create a square.
Rectangle/square (centered)	Draw a rectangle/square starting at the center. Using the left mouse button, click-and-drag to create a rectangle. Using the right mouse button (or Ctrl+click), click-and-drag to create a square.
Ellipse/circle	Draw an ellipse/circle starting at the perimeter. Using the left mouse button, click-and-drag to create an ellipse. Using the right mouse button (or Ctrl+click), click-and-drag to create a circle.
Ellipse/circle (centered)	Draw an ellipse/circle starting at the center. Using the left mouse button, click-and-drag to create an ellipse. Using the right mouse button (or Ctrl+click), click-and-drag to create a circle.
Polygon	Draw a polygon. You can close the polygon by pressing the right mouse button. Clicking at the starting vertex also closes the polygon.
Rotate	Rotate selected objects.
Export Geometry Description, Set Formula, Labels	Export the Geometry Description matrix gd, the set formula string sf, and the Name Space matrix ns (labels) to the main workspace.

Rotate

Rotate opens a dialog box where you can enter the angle of rotation in degrees. The selected objects are then rotated by the number of degrees that you specify. The rotation is done counter clockwise for positive rotation angles. By default, the rotation center is the center-of-mass of the selected objects. If the Use center-of-mass option is not selected, you can enter a rotation center (xc,yc) as a 1-by-2 MATLAB vector such as [-0.4 0.3].

Back to Top

Boundary Menu

Boundary Mode	Enter the boundary mode.
Specify Boundary Conditions	Specify boundary conditions for the selected boundaries. If no boundaries are selected, the entered boundary condition applies to all boundaries.
Show Edge Labels	Toggle the labeling of the edges (outer boundaries and subdomain borders) on/off. The edges are labeled using the column number in the Decomposed Geometry matrix.
Show Subdomains Labels	Toggle the labeling of the subdomains on/off. The subdomains are labeled using the subdomain numbering in the Decomposed Geometry matrix.
Remove Subdomain Border	Remove selected subdomain borders.
Remove All Subdomain Borders	Remove all subdomain borders.
Export Decomposed Geometry, Boundary Cond's	Export the Decomposed Geometry matrix g and the Boundary Condition matrix b to the main workspace.

Specify Boundary Conditions

Specify boundary conditions displays a dialog box in which you can specify the boundary condition for the selected boundary segments. There are three different condition types:

• Generalized Neumann conditions, where the boundary condition is determined by the coefficients q and g according to the following equation:

  

  In the system cases, q is a 2-by-2 matrix and g is a 2-by-1 vector.

• Dirichlet conditions: u is specified on the boundary. The boundary condition equation is hu = r, where h is a weight factor that can be applied (normally 1).

  In the system cases, h is a 2-by-2 matrix and r is a 2-by-1 vector.

• Mixed boundary conditions (system cases only), which is a mix of Dirichlet and Neumann conditions. q is a 2-by-2 matrix, g is a 2-by-1 vector, h is a 1-by-2 vector, and r is a scalar.

The following figure shows the boundary condition dialog box for the generic system PDE.

For boundary condition entries you can use the following variables in a valid MATLAB expression:

• The 2-D coordinates x and y.

• A boundary segment parameter s, proportional to arc length. s is 0 at the start of the boundary segment and increases to 1 along the boundary segment in the direction indicated by the arrow.

• The outward normal vector components nx and ny. If you need the tangential vector, it can be expressed using nx and ny since t_x = -n_y and t_y = n_x.

• The solution u.

• The time t.

Note   If the boundary condition is a function of the solution u, you must use the nonlinear solver. If the boundary condition is a function of the time t, you must choose a parabolic or hyperbolic PDE.

Examples: (100-80*s).*nx, and cos(x.^2)

In the nongeneric application modes, the Description column contains descriptions of the physical interpretation of the boundary condition parameters.

Back to Top

PDE Menu

PDE Mode	Enter the partial differential equation mode.
Show Subdomain Labels	Toggle the labeling of the subdomains on/off. The subdomains are labeled using the subdomain numbering in the decomposed geometry matrix.
PDE Specification	Open dialog box for entering PDE coefficients and types.
Export PDE Coefficients	Export current PDE coefficients to the main workspace. The resulting workspace variables are strings.

PDE Specification

PDE Specification opens a dialog box where you enter the type of partial differential equation and the applicable parameters. The dimension of the parameters is dependent on the dimension of the PDE. The following description applies to scalar PDEs. If a nongeneric application mode is selected, application-specific PDEs and parameters replace the standard PDE coefficients. For a thorough description of the different application modes, see Application Modes.

Each of the coefficients c, a, f, and d can be given as a valid MATLAB expression for computing coefficient values at the triangle centers of mass. The following variables are available:

• x and y: The x- and y-coordinates

• u: The solution

• ux, uy: The x and y derivatives of the solution

• t: The time

Note   If the PDE coefficient is a function of the solution u or its derivatives ux and uy, you must use the nonlinear solver. If the PDE coefficient is a function of the time t, you must choose a parabolic or hyperbolic PDE.

You can also enter the name of a user-defined MATLAB function that accepts the arguments (p,t,u,time). For an example, type the function circlef.

c can be a scalar or a 2-by-2 matrix. The matrix c can be used to model, e.g., problems with anisotropic material properties.

If c contains two rows, they are the c_1,1 and c_2,2 elements of a 2-by-2 symmetric matrix

If c contains three rows, they are the c_1,1, c_1,2, and c_2,2 elements of a 2-by-2 symmetric matrix (c_2,1 = c_1,2)

If c contains four rows, they are the c_1,1, c_2,1, c_1,2, and c_2,2 elements of the 2-by-2 preceding matrix.

The available types of PDEs are

• Elliptic. The basic form of the elliptic PDE is

  

  The parameter d does not apply to the elliptic PDE.

• Parabolic. The basic form of the parabolic PDE is

  

  with initial values u0 = u(t₀).

• Hyperbolic. The basic form of the hyperbolic PDE is

  

  with initial values u0 = u(t₀) and ut0 = (t₀)

• Eigenmodes. The basic form of the PDE eigenvalue problem is

  

  The parameter f does not apply to the eigenvalue PDE.

In the system case, c is a rank four tensor, which can be represented by four 2-by-2 matrices, c11, c12, c21, and c22. They can be entered as one, two, three, or four rows—see the preceding scalar case. a and d are 2-by-2 matrices, and f is a 2-by-1 vector. The PDE Specification dialog box for the system case is shown in the following figure.

Back to Top

Mesh Menu

Mesh Mode	Enter mesh mode.
Initialize Mesh	Build and display an initial triangular mesh.
Refine Mesh	Uniformly refine the current triangular mesh.
Jiggle Mesh	Jiggle the mesh.
Undo Mesh Change	Undo the last mesh change. All mesh generations are saved, so repeated Undo Mesh Change eventually brings you back to the initial mesh.
Display Triangle Quality	Display a plot of the triangular mesh where the individual triangles are colored according to their quality. The quality measure is a number between 0 and 1, where triangles with a quality measure greater than 0.6 are acceptable. For details on the triangle quality measure, see pdetriq.
Show Node Labels	Toggle the mesh node labels on/off. The node labels are the column numbers in the Point matrix p.
Show Triangle Labels	Toggle the mesh triangle labels on/off. The triangle labels are the column numbers in the triangle matrix t.
Parameters	Open dialog box for modification of mesh generation parameters.
Export Mesh	Export Point matrix p, Edge matrix e, and Triangle matrix t to the main workspace.

Parameters

Parameters opens a dialog box containing mesh generation parameters. The parameters used by the mesh initialization algorithm initmesh are:

• Maximum edge size: Largest triangle edge length (approximately). This parameter is optional and must be a real positive number.

• Mesh growth rate: The rate at which the mesh size increases away from small parts of the geometry. The value must be between 1 and 2. The default value is 1.3, i.e., the mesh size increases by 30%.

• Jiggle mesh: Toggles automatic jiggling of the initial mesh on/off.

The parameters used by the mesh jiggling algorithm jigglemesh are:

• Jiggle mode: Select a jiggle mode from a pop-up menu. Available modes are on, optimize minimum, and optimize mean. on jiggles the mesh once. Using the jiggle mode optimize minimum, the jiggling process is repeated until the minimum triangle quality stops increasing or until the iteration limit is reached. The same applies for the optimize mean option, but it tries to increase the mean triangle quality.

• Number of jiggle iterations: Iteration limit for the optimize minimum and optimize mean modes. Default: 20.

Finally, for the mesh refinement algorithm refinemesh, the Refinement method can be regular or longest. The default refinement method is regular, which results in a uniform mesh. The refinement method longest always refines the longest edge on each triangle.

Back to Top

Solve Menu

Solve PDE	Solve the partial differential equation for the current CSG model and triangular mesh, and plot the solution (the automatic solution plot can be disabled).
Parameters	Open dialog box for entry of PDE solve parameters.
Export Solution	Export the PDE solution vector u and, if applicable, the computed eigenvalues l to the main workspace.

Parameters

Solve Parameters Dialog Box for Elliptic PDEs

Parameters opens a dialog box where you can enter the solve parameters. The set of solve parameters differs depending on the type of PDE.

• Elliptic PDEs. By default, no specific solve parameters are used, and the elliptic PDEs are solved using the basic elliptic solver assempde. Optionally, the adaptive mesh generator and solver adaptmesh can be used. For the adaptive mode, the following parameters are available:

  • Adaptive mode. Toggle the adaptive mode on/off.

  • Maximum number of triangles. The maximum number of new triangles allowed (can be set to Inf). A default value is calculated based on the current mesh.

  • Maximum number of refinements. The maximum number of successive refinements attempted.

  • Triangle selection method. There are two triangle selection methods, described below. You can also supply your own function.

    • Worst triangles. This method picks all triangles that are worse than a fraction of the value of the worst triangle (default: 0.5). For more details, see pdetriq.

    • Relative tolerance. This method picks triangles using a relative tolerance criterion (default: 1E-3). For more details, see pdeadgsc.

    • User-defined function. Enter the name of a user-defined triangle selection method. See pdedemo7 for an example of a user-defined triangle selection method.

  • Function parameter. The function parameter allows fine-tuning of the triangle selection methods. For the worst triangle method (pdeadworst), it is the fraction of the worst value that is used to determine which triangles to refine. For the relative tolerance method, it is a tolerance parameter that controls how well the solution fits the PDE.

  • Refinement method. Can be regular or longest. See the Parameters dialog box description in Mesh Menu.

  If the problem is nonlinear, i.e., parameters in the PDE are directly dependent on the solution u, a nonlinear solver must be used. The following parameters are used:

  • Use nonlinear solver. Toggle the nonlinear solver on/off.

  • Nonlinear tolerance. Tolerance parameter for the nonlinear solver.

  • Initial solution. An initial guess. Can be a constant or a function of x and y given as a MATLAB expression that can be evaluated on the nodes of the current mesh.

    Examples: 1, and exp(x.*y). Optional parameter, defaults to zero.

  • Jacobian. Jacobian approximation method: fixed (the default), a fixed point iteration, lumped, a "lumped" (diagonal) approximation, or full, the full Jacobian.

  • Norm. The type of norm used for computing the residual. Enter as energy for an energy norm, or as a real scalar p to give the lp norm. The default is Inf, the infinity (maximum) norm.

    Note   The adaptive mode and the nonlinear solver can be used together.

  • Parabolic PDEs. The solve parameters for the parabolic PDEs are:

    • Time. A MATLAB vector of times at which a solution to the parabolic PDE should be generated. The relevant time span is dependent on the dynamics of the problem.

      Examples: 0:10, and logspace(-2,0,20)

    • u(t0). The initial value u(t₀) for the parabolic PDE problem The initial value can be a constant or a column vector of values on the nodes of the current mesh.

    • Relative tolerance. Relative tolerance parameter for the ODE solver that is used for solving the time-dependent part of the parabolic PDE problem.

    • Absolute tolerance. Absolute tolerance parameter for the ODE solver that is used for solving the time-dependent part of the parabolic PDE problem.

    Solve Parameters Dialog Box for Hyperbolic PDEs

    

  • Hyperbolic PDEs. The solve parameters for the hyperbolic PDEs are:

    • Time. A MATLAB vector of times at which a solution to the hyperbolic PDE should be generated. The relevant time span is dependent on the dynamics of the problem.

      Examples: 0:10, and logspace(-2,0,20)

    • u(t0). The initial value u(t₀) for the hyperbolic PDE problem. The initial value can be a constant or a column vector of values on the nodes of the current mesh.

    • u'(t0). The initial value (t₀) for the hyperbolic PDE problem. You can use the same formats as for u(t0).

    • Relative tolerance. Relative tolerance parameter for the ODE solver that is used for solving the time-dependent part of the hyperbolic PDE problem.

    • Absolute tolerance. Absolute tolerance parameter for the ODE solver that is used for solving the time-dependent part of the hyperbolic PDE problem.

      Solve Parameters Dialog Box for Eigenvalue PDEs

      

  • Eigenvalue problems. For the eigenvalue PDE, the only solve parameter is the Eigenvalue search range, a two-element vector, defining an interval on the real axis as a search range for the eigenvalues. The left side can be -Inf.

    Examples: [0 100], [-Inf 50]

Back to Top

Plot Menu

Plot Solution	Display a plot of the solution.
Parameters	Open dialog box for plot selection.
Export Movie	If a movie has been recorded, the movie matrix M is exported to the main workspace.

Parameters

Plot Selection Dialog Box

Parameters opens a dialog box containing options controlling the plotting and visualization.

The upper part of the dialog box contains four columns:

• Plot type (far left) contains a row of six different plot types, which can be used for visualization:

  • Color. Visualization of a scalar property using colored surface objects.

  • Contour. Visualization of a scalar property using colored contour lines. The contour lines can also enhance the color visualization when both plot types (Color and Contour) are checked. The contour lines are then drawn in black.

  • Arrows. Visualization of a vector property using arrows.

  • Deformed mesh. Visualization of a vector property by deforming the mesh using the vector property. The deformation is automatically scaled to 10% of the problem domain. This plot type is primarily intended for visualizing x- and y-displacements (u and v) for problems in structural mechanics. If no other plot type is selected, the deformed triangular mesh is displayed.

  • Height (3-D plot). Visualization of a scalar property using height (z-axis) in a 3-D plot. 3-D plots are plotted in separate figure windows. If the Color and Contour plot types are not used, the 3-D plot is simply a mesh plot. You can visualize another scalar property simultaneously using Color and/or Contour, which results in a 3-D surface or contour plot.

  • Animation. Animation of time-dependent solutions to parabolic and hyperbolic problems. If you select this option, the solution is recorded and then animated in a separate figure window using the MATLAB movie function.

A color bar is added to the plots to map the colors in the plot to the magnitude of the property that is represented using color or contour lines.

• Property contains four pop-up menus containing lists of properties that are available for plotting using the corresponding plot type. From the first pop-up menu you control the property that is visualized using color and/or contour lines. The second and third pop-up menus contain vector valued properties for visualization using arrows and deformed mesh, respectively. From the fourth pop-up menu, finally, you control which scalar property to visualize using z-height in a 3-D plot. The lists of properties are dependent on the current application mode. For the generic scalar mode, you can select the following scalar properties:

  • u. The solution itself.

  • abs(grad(u)). The absolute value of ∇u, evaluated at the center of each triangle.

  • abs(c*grad(u)). The absolute value of c · ∇u, evaluated at the center of each triangle.

  • user entry. A MATLAB expression returning a vector of data defined on the nodes or the triangles of the current triangular mesh. The solution u, its derivatives ux and uy, the x and y components of c · ∇u, cux and cuy, and x and y are all available in the local workspace. You enter the expression into the edit box to the right of the Property pop-up menu in the User entry column.

    Examples: u.*u, x+y

  The vector property pop-up menus contain the following properties in the generic scalar case:

  • -grad(u). The negative gradient of u, -∇u.

  • -c*grad(u). c times the negative gradient of u, -c · ∇u.

  • user entry. A MATLAB expression [px; py] returning a 2-by-ntri matrix of data defined on the triangles of the current triangular mesh (ntri is the number of triangles in the current mesh). The solution u, its derivatives ux and uy, the x and y components of c · ∇u, cux and cuy, and x and y are all available in the local workspace. Data defined on the nodes is interpolated to triangle centers. You enter the expression into the edit field to the right of the Property pop-up menu in the User entry column.

    Examples: [ux;uy], [x;y]

For the generic system case, the properties available for visualization using color, contour lines, or z-height are u, v, abs(u,v), and a user entry. For visualization using arrows or a deformed mesh, you can choose (u,v) or a user entry. For applications in structural mechanics, u and v are the x- and y-displacements, respectively.

For the visualization options in the other application modes, see Application Modes. The variables available in the local workspace for a user entered expression are the same for all scalar and system modes (the solution is always referred to as u and, in the system case, v).

• User entry contains four edit fields where you can enter your own expression, if you select the user entry property from the corresponding pop-up menu to the left of the edit fields. If the user entry property is not selected, the corresponding edit field is disabled.

• Plot style contains three pop-up menus from which you can control the plot style for the color, arrow, and height plot types respectively. The available plot styles for color surface plots are

  • Interpolated shading. A surface plot using the selected colormap and interpolated shading, i.e., each triangular area is colored using a linear, interpolated shading (the default).

  • Flat shading. A surface plot using the selected colormap and flat shading, i.e., each triangular area is colored using a constant color.

  You can use two different arrow plot styles:

  • Proportional. The length of the arrow corresponds to the magnitude of the property that you visualize (the default).

  • Normalized. The lengths of all arrows are normalized, i.e., all arrows have the same length. This is useful when you are interested in the direction of the vector field. The direction is clearly visible even in areas where the magnitude of the field is very small.

  For height (3-D plots), the available plot styles are:

  • Continuous. Produces a "smooth" continuous plot by interpolating data from triangle midpoints to the mesh nodes (the default).

  • Discontinuous. Produces a discontinuous plot where data and z-height are constant on each triangle.

A total of three properties of the solution—two scalar properties and one vector field—can be visualized simultaneously. If the Height (3-D plot) option is turned off, the solution plot is a 2-D plot and is plotted in the main axes of the pdetool GUI. If the Height (3-D plot) option is used, the solution plot is a 3-D plot in a separate figure window. If possible, the 3-D plot uses an existing figure window. If you would like to plot in a new figure window, simply type figure at the MATLAB command line.

Additional Plot Control Options

In the middle of the dialog box are a number of additional plot control options:

• Plot in x-y grid. If you select this option, the solution is converted from the original triangular grid to a rectangular x-y grid. This is especially useful for animations since it speeds up the process of recording the movie frames significantly.

• Show mesh. In the surface plots, the mesh is plotted using black color if you select this option. By default, the mesh is hidden.

• Contour plot levels. For contour plots, the number of level curves, e.g., 15 or 20 can be entered. Alternatively, you can enter a MATLAB vector of levels. The curves of the contour plot are then drawn at those levels. The default is 20 contour level curves.

  Examples: [0:100:1000], logspace(-1,1,30)

• Colormap. Using the Colormap pop-up menu, you can select from a number of different colormaps: cool, gray, bone, pink, copper, hot, jet, hsv, and prism.

• Plot solution automatically. This option is normally selected. If turned off, there will not be a display of a plot of the solution immediately upon solving the PDE. The new solution, however, can be plotted using this dialog box.

For the parabolic and hyperbolic PDEs, the bottom right portion of the Plot Selection dialog box contains the Time for plot parameter.

Time for plot. A pop-up menu allows you to select which of the solutions to plot by selecting the corresponding time. By default, the last solution is plotted.

Also, the Animation plot type is enabled. In its property field you find an Options button. If you press it, an additional dialog box appears. It contains parameters that control the animation:

• Animation rate (fps). For the animation, this parameter controls the speed of the movie in frames per second (fps).

• Number of repeats. The number of times the movie is played.

• Replay movie. If you select this option, the current movie is replayed without rerecording the movie frames. If there is no current movie, this option is disabled.

  

For eigenvalue problems, the bottom right part of the dialog box contains a pop-up menu with all eigenvalues. The plotted solution is the eigenvector associated with the selected eigenvalue. By default, the smallest eigenvalue is selected.

You can rotate the 3-D plots by clicking the plot and, while keeping the mouse button down, moving the mouse. For guidance, a surrounding box appears. When you release the mouse, the plot is redrawn using the new viewpoint. Initially, the solution is plotted using -37.5 degrees horizontal rotation and 30 degrees elevation.

If you click the Plot button, the solution is plotted immediately using the current plot setup. If there is no current solution available, the PDE is first solved. The new solution is then plotted. The dialog box remains on the screen.

If you click the Done button, the dialog box is closed. The current setup is saved but no additional plotting takes place.

If you click the Cancel button, the dialog box is closed. The setup remains unchanged since the last plot.

Back to Top

Window Menu

From the Window menu, you can select all currently open MATLAB figure windows. The selected window is brought to the front.

Back to Top

Help Menu

Help	Display a brief help window.
About	Display a window with some program information.

Back to Top

Graphical User Interface

The Toolbar

© 1984-2009- The MathWorks, Inc.    -   Site Help   -   Patents   -   Trademarks   -   Privacy Policy   -   Preventing Piracy   -   RSS