Sometimes grid cells are located on land while making grids. So, we can use the delete grid nodes feature to remove those cells. The delete grid node feature is varied and can be accessed from different options as described below for each case. The user can select a proper approach for a specific need.
Delete single grid node
Suppose that a grid is loaded in the workplace and the user wants to delete some grid nodes of that grid.
- LMC on the grid layer in the Layer Control to select the grid want to work with.
- From the main toolbar, select Delete node button then LMC on a grid node to delete node as shown in Delete Grid Node. Keeping LMC on other nodes will delete the selected nodes. To escape the delete grid node function, click the select object button from the main toolbar or press S key.
Figure 1 Delete single grid node.
Delete grid nodes with a grid block selection
For this option, we can remove nodes inside or outside of the selected grid block.
- LMC on the grid layer in the Layer Control to select the grid want to work with.
- From the main toolbar, select Select object button then LMC on a grid node, the selected node will be highlighted.
- Hold the Shift key and LMC on another grid node (that one is not on the same grid line with the previous one), and the grid block defined by the two selected nodes will be highlighted (Delete Grid Node).
After step 3 above, now we can delete nodes inside by accessing the Grid menu, select Delete Selected Grid Block option, or RMC to display options then select Grid Grid Block option, as shown in Delete Grid Node. To delete grid nodes outside a grid block, select Delete Grid Nodes Outside a Block option from RMC's options, as shown in Delete Grid Node.
Figure 2 Select a grid block.
Figure 3 Delete nodes inside a grid block.
Figure 4 Delete grid nodes outside a grid block.
Delete grid nodes inside polygon
From the main toolbar, select Add a new polyline button then start drawing the polyline by LMC and end by RMC (the polyline overlay the grid) as shown in Delete Grid Nodes#Figure 5. In case, the polyline file is available from external source, the user can skip the drawing polyline steps and load the polyline file into the workplace.
- Select the Select object button from the main toolbar, LMC on the polyline, it will be highlighted.
- LMC on the grid layer in the Layer Control (the selected polygon is still highlighted).
- Now RMC, a number of options will be displayed, select Delete Grid Nodes Inside the Selected Polygon to delete the grid points inside the polygon as shown in Delete Grid Nodes#Figure 6
Figure 5 Add a new polyline.
Figure 6 Delete grid nodes inside a polygon.
Delete grid nodes outside polygon
Apply from steps 1 to 3 similarly to the delete grid nodes inside a polygon described above, in step 4, select Delete Grid Nodes Outside the Selected Polygon to delete the grid points outside the polygon as shown in Delete Grid Nodes#Figure 7
Figure 7 Delete grid nodes outside a polygon.