The delete grid nodes feature is used to remove unwanted cells. This is especially useful when there are cells outside the waterbody. The delete grid node feature can be used to delete a single node, a block of cells, or cells within a polygon as described below.
Delete single grid node
Suppose that Once a grid is loaded in the workplace and the user want , the following steps describe how to delete grid node on that gridthe unwanted grid nodes.
- LMC on the grid layer in the Layer Control to select the grid want to working work with.
- From the main toolbar, select the Delete node button then LMC on a grid node to delete node as shown in Figure 1 (some nodes inside the blue ellipse has been deleted) 1149927473. Keeping LMC on other nodes will delete those nodes also. To end using the delete function, click the select object button from the main toolbar or press the S key.
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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 working be worked with.
- From the main toolbar, select press Select objectObject button then LMC on a grid node, the selected node will be highlighted.
- From Hold the keyboard, hold the Shift key and LMC on another grid node (that one is not on the same grid line as the previous one), and the grid block defined by the two selected nodes will be highlighted (1149927473).
After step 3, we can delete nodes inside by accessing the Grid menu, and selecting the Delete Selected Grid Block option. Alternatively, RMC to display options then select Grid Grid Block option, as shown in 1149927473. To delete grid nodes outside a grid block, select Delete Grid
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Nodes Outside a Block option from the RMC options, as shown in 1149927473.
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Figure 2 Delete grid nodes inside . Select a grid block.
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Figure 3 Grid nodes deleted after using inside a grid block option.
Delete
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nodes inside a grid block
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Figure 4. Delete grid nodes outside a grid block.
Delete grid nodes with a polygon
For this option, we can remove nodes inside or outside of a polygon. The polygon can be loaded from an external file or after drawing a new one. You can also use the Polygon Selection Mode to select grid nodes.
- From the main toolbar, select click Add a new polyline button then start draw drawing the polyline polygon by LMC and end by RMC (the polyline overlay polygon overlays the grid) as shown in Figure 5. In case, the polyline 1149927473. If the polygon file is available from an external source, the user can skip the drawing polyline polygon steps and load the polyline polygon file into the workplace.
- Select the Select object button from the main toolbar, select the overlay layer (the polygon layer) in the Layer Control panel. Then LMC on the polyline, polygon and it will be highlighted.
- LMC on the grid layer in the Layer Control (. it means selecting the grid that we want to delete nodes.
- While the selected polygon is still highlighted).Now RMC, a number of options will be displayed, select , RMC to display various options. Select Delete Grid Nodes Inside the Selected Polygon to delete the grid points nodes inside the polygon or selecting Delete Grid Nodes Outside the Selected Polygon to delete the grid nodes outside the polygonas shown in Figure 6 1149927473.
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Figure 5Add . Draw a new polylinepolygon that overlays the grid.
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Figure 6Delete grid nodes inside a polygon.Delete grid nodes
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Apply from step 1 to 3 similarly to the delete grid nodes inside a polygon described above, in the step 4, select Delete Grid Nodes Outside the Selected Polygon to delete the grid points outside the polygon as shown in Figure 7
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Figure 7 Delete grid nodes inside/outside a polygon.