Limiting Computational Boundary with Small Grid Size
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I have elevation points (in random order) for an entire town. This is about 42 square miles and over 3 million points. These do successfully import into the GDS. This creates a large and slow file.
I only need to model reaches on the order of 1 or 2 square miles, and I would be fine with multiple smaller files. I need a small grid size (~25 feet). Since a grid system needs to be created before a computational boundary, I get a "Not Enough Memory" error when trying to do so.
To my knowledge, there is no way to clip the project area in the GDS. How would you suggest I could continue this project?
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There are two options in this case.
1. Delete n-values outside the area of interest with a polygon in the GDS. This tool is found in under the menu Design/Elevation Points/Delete Elevation Points from Selected Area. Select that option and isolate the points within the area of interest using a polygon. Then click File/Save Elevation Points... to make a *.pts file of the area of interest. It will then be possible to run the old interpolation method found in Lesson 1 of the Workshop Lessons.
2. This method uses new GDS tools that perform the interpolation outside the GDS. Create a polygon of the area of interest using GIS software. Then open a new project from a shape file using the Area of Interest shape file. This will define the limits of the grid system. Then overlay the grid system and draw the boundary. Finally, use the new interpolation tool to assign the grid element elevation. Do not import the data points because they will be interpolated outside the GDS. This takes the least amount of time but the latest GDS is needed.
Download the latest GDS at http://www.flo-2d.com/executable-updates
Download the Interpolation Instructions at http://www.flo-2d.com/wp-content/uploads/FLO-2D_GDS_New_Interpolation_Method.pdfJust paste the links into a browser
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I have manually clipped the elevation points in Microsoft Access as much as I could. I imported the new points, created a grid, and saved the .TOP file. I now cannot return to (open) that .TOP file. I receive an error that states "ERROR 2305081819: Invalid procedure call or argument". How shall I continue?
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And even with starting over, creating a grid, and defining a computational boundary, when I click OK in the Grid Element Elevation Interpolation dialog box, the program crashes, and I get an error that "FLO_2D Grid Developer has encountered a problem and needs to close." All data is lost.
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Use option 2 but instead of using a shape file to define your project extents just open a new project using GDS and define the project extents. You can also use a CAD file.
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