Create Nodes From Variable Grid
This function will take string files created by the Create Variable Grid function and produce new string files which contain the points at the centre of each of the grid cells.
This function was designed for use with the groundwater modelling modules, e.g. FLOW 3D and MOC, where variable size grid models are used, however it can be used in any situation where a grid of points is required where the spacings between rows and columns in the grid varies.
To run this function: Choose File tools > Grid tools > Nodes from variable grid, or...
Define the input files
Enter the Location and ID range of the string files which are to be processed with this function. Note that you should only use string files which have been created using the Create Variable Grid function as the strings and segments of strings must be in the correct order for the results to be meaningful. See Create Variable Grid for details of the strings which are created.
Y string number X string number
Enter the string numbers which represent the strings for the Y direction (the rows) and the X direction (the columns). Each string will consist of a number of segments where each segment has only two points. The segments in each of the strings must exist in ascending order of Y value or X value.
Define the outputs
Enter the Location of the file which will contain the node points for each of the grid cells from the input file. The cell node points are the points which are in the centre of each of the grid cells.
String number
Enter the String number which is to be used for the node points.
D field for delta X, D field for delta Y
The delta X and delta Y values are simply the size of each of the grid cells in the X and Y directions respectively, that is, the extent of the cell in the X direction and the Y direction.
Enter the number of the description field which will contain the delta X and delta Y values for the grid cell sizes. Some groundwater modelling programs, notably FLOW3D and MOC require the cell size to be able to run a model. The default field numbers here are designed to work with these two modelling programs although for other purposes you may use any description field numbers which suit your purpose.
Result
The string files specified are processed individually and one string file is created for each of the input files. The string file which is created has one segment for each of the rows of grid nodes and each segment contains one point for each column.
The delta X and delta Y values are saved to the specified description fields. The Z value of each of the points is made to be the same as the file ID number. This is a requirement for the groundwater modelling programs mentioned above.
Below is a diagram which shows the arrangement of string segments in the input string file and the resultant grid node points which are created.
