Grid Point Value

Use the Grid and Image > Utilities > Point Values menu option (GRIDVALUE GX) to calculate and report the grid value at a selected location from up to four grid files.

Point Values dialog options

Grid 1 Grid 2 Grid 3 Grid 4	Select up to four grids to report. Script Parameter: GRIDVALUE.GRD1 Script Parameter: GRIDVALUE.GRD2 Script Parameter: GRIDVALUE.GRD3 Script Parameter: GRIDVALUE.GRD4
[Point]	After pressing this button, you will be able to select a point on the current map. The values of each of the specified grids will be reported in a separate dialog - see below.

Grid Values at a Point dialog options

Map X Map Y	This is the X, Y location that has been selected. You can change these values directly in the dialog and then click on the Calc button to determine the grid values at the specified location.
Grid name	The name of each grid specified appears with the grid value at the selected point.
[Point]	After pressing this button, you will be able to select a new point on the current map. The values of each of the specified grids will be reported. You can also just press return, then click on a new location.
[Calc]	If you have changed the X, Y values directly, this button will calculate the grid values at the new location.

Application Notes

The grid value obtained at any point on a map is dependent on the display (rendering) mode of the grid, which is controlled by the Smoothing button located on the Grid Viewer toolbar or the Map Manager toolbar of your grid or map, respectively:

• "Smoothed" display: the grid is interpolated to a smooth image at the screen resolution. Click here The four adjacent grid values (irrespective of the cell sizes) are used for the linear interpolation as following: if the location falls exactly on a grid point, it returns that value; if the location is on an “edge” (a line joining points in “X” or in “Y”), it linearly interpolates between those two points (if either is a dummy, it returns a dummy); if the location is inside the square defined by the four points, it interpolates the values linearly in X and in Y (if any point is a dummy, it returns a dummy). for details on how the grid value is obtained.
• "Pixelated" display: the grid resolution is honoured and the image appears pixelated. Click here The value of the closest “corner” is returned. Locations exactly at the half-way point between two grid values are rounded down to the lower-index value. for details on how the grid value is obtained.