Defines the domain where you solve the partial differential equation. You must manually select the polymorphic instance to use.


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Inputs/Outputs

  • cNI__PDE_lvlib_NI__PDElvclass.png PDE in —

    PDE in is the class that stores the data of the equation.

  • cnclst.png X —

    X specifies the uniform mesh grid along the x-axis.

  • cdbl.png start x —

    start x specifies the starting mesh grid point x0 along the x-axis. start x must be less than end x. The default is 0.

  • cdbl.png end x —

    end x specifies the ending mesh grid point xm along the x-axis. end x must be greater than start x. The default is 1.

  • ci32.png # of x-points —

    # of x-points specifies the number of grid points along the x-axis. # of x-points is equal to m + 1 and must be greater than 2. The default is 11.

  • cnclst.png Y —

    Y specifies the uniform mesh grid along the y-axis.

  • cdbl.png start y —

    start y specifies the starting mesh grid point y0 along the y-axis. start y must be less than end y. The default is 0.

  • cdbl.png end y —

    end y specifies the ending mesh grid point yn along the y-axis. end y must be greater than start y. The default is 1.

  • ci32.png # of y-points —

    # of y-points specifies the number of grid points along the y-axis. # of y-points is equal to n + 1 and must be greater than 2. The default is 11.

  • cerrcodeclst.png error in (no error) —

    error in describes error conditions that occur before this node runs. This input provides standard error in functionality.

  • iNI__PDE_lvlib_NI__PDElvclass.png PDE out —

    PDE out returns PDE in with the domain.

  • ierrcodeclst.png error out —

    error out contains error information. This output provides standard error out functionality.

    • The following illustration shows the uniform mesh grid on a rectangular domain with the default values. Both the x- and y-axes range from 0 to 1 with 11 evenly spaced grid points. The black circle points are the points on the boundary of the rectangular domain. The red square points are the inner points on the mesh grid.

    The following illustration shows the unit circle on a polygonal domain. The black circle points are the points on the boundary of the domain that generate evenly on the unit circle. The red square points are the inner grid points that generate automatically with the default of grid factor.

    Note You must specify the boundary points in a clockwise or counterclockwise direction.

    The following block diagram illustrates a VI that defines the polygonal domain, as shown in the previous illustration.

    If you do not wire a value to Grid Points, LabVIEW generates the boundary points automatically based on grid factor, which determines the density of the grid points. LabVIEW performs triangulation on the grid points before solving the equation. The grid factor approximates the ratio of the average area of the triangles to the area of the whole polygonal domain.

    If you have prior knowledge of the unknown function, wire a value to Grid Points. You can use sparse grid points in areas where the unknown function varies smoothly and use dense grid points in areas where the unknown function varies sharply. For some problems, this flexibility in the choice of grid points can return better results than a set of uniformly distributed grid points.

    Examples

    Refer to the following example files included with LabVIEW.

    • labview\examples\Mathematics\Differential Equations - PDE\PDE Flexible Element.vi
    • labview\examples\Mathematics\Differential Equations - PDE\PDE String Vibration.vi
    • labview\examples\Mathematics\Differential Equations - PDE\PDE Thermal Distribution.vi