Grid 1D, Grid 2D, and Grid 3D
Adding a Grid 1D (), Grid 2D (), or Grid 3D node () from the More Data Sets, More 2D Data Sets, or More 3D Data Sets submenus creates a data set that can evaluate functions or other data sets on a domain with a grid, including global functions also where there is no domain mesh; for example, you can evaluate BEM and far-field operators. All functions in the same list as the selected function can be evaluated. The domain is an interval for Grid 1D, a rectangle for Grid 2D, and a block for Grid 3D. The domain does not need to have the same dimension as the number of arguments to the function. To plot functions, use a line graph in 1D, for example, by pointing to the Grid 1D data set in a 1D Plot Group (or similarly for Grid 2D and Grid 3D). Grid data sets always use the spatial frame when evaluating outside the meshed domain.
Click the Plot button () to visualize the grid data set in a plot.
Data
From the Source list, select Data set (the default) to evaluate an expression based on a solution data set or select Function to evaluate a function.
For data sets, select an available solution data set from the Data set list, or select None to not use any data set. It is only possible to evaluate globally defined expressions and expressions that depend on spatial coordinates. Using the ati operator with the extra argument 'mi', you can also access domain variables defined on domains where the grid points are located.
For functions, select the function to create a data set for from the Function list: None, All, or any of the defined functions in the model. Select All to make the Grid data set point to all functions in the list rather than to a specific function, which can be useful, for example, to plot several functions together in the same plot group.
For functions, there is also a Refresh button, that you can click to update the source for functions that read files (Elevation, Image, and Interpolation).
The plot of the grid data uses the number of points specified in the Resolution section below, mixing uniformly distributed points with points taken from the function, including local minima and maxima.
Parameter Bounds
Available fields are based on the Grid data set’s dimension. Enter a Name. The First parameter, Second parameter (Grid 2D and Grid 3D), and Third parameter (Grid 3D only) default names are x, y, and z, respectively. For each parameter, enter a Minimum lower bound (the defaults are 0) and a Maximum upper bound (the defaults are 1) for the first, second, and third dimension of the domain.
Resolution
Enter a Resolution. This is the number of points into which each dimension is discretized. The defaults are 1000 (Function 1D), 100 (Function 2D), and 30 (Function 3D), and the valid range is between 2 and 1,000,000 points. A high resolution might require significant computational resources.
For an example of a 1D grid data set and with the AC/DC Module, see A Geoelectrical Forward Problem: Application Library path ACDC_Module/Other_Industrial_Applications/geoelectrics.