SAGA Creating a Grid from Points: Difference between revisions
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Created page with "<ol> =Introduction= This is an excellent way of visualising check files such as the _zpt_check.mif that is written by TUFLOW. This check file is outputted after all elevation da..." |
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=Method=
<li>Open the points shapes layer that you wish to create a grid from.</li>
<li>From the menu items select ''Modules >> Grid >> Gridding >> Interpolation from Points >> Inverse Distance Weighted''.</li>
[[File:Saga create grid IDW1.png|frame|none|Create IDW Grid from Points]]
<li>In the IDW dialogue set the following parameters:
*Points - The desired Points Shapefile
*Attribute - The attribute field to use
*Distance weighting Parameters - Set these as desired
*Search Radius - Set this to the cell size (to avoid the gird extending beyond the data)
*Maximum Number of Points - The higher the value the more smoothing (for a DEM from zpt_check file use a small number)
Select ''Okay''.<br></li>
[[File:Saga create grid IDW2.png|frame|none|Setting IDW parameters]]
<li>Set the cell size for the resultant grid, for a DEM from a _zpt_check_P.shp use half the TUFLOW cell size. The other parameters are automatically determined from the input data.</li>
[[File:Saga create grid IDW3.png|frame|none|Set Grid Cell Size (half TUFLOW Cell Size)]]
<li>A new grid has been created, add this to a map to view.</li>
[[File:Saga create grid IDW4.png|frame|none|IDW created from _zpt_check_P.shp]]
</ol>
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