Introducing Geographic Information Systems with ArcGIS: A Workbook Approach to Learning GIS, 3rd Edition

Making Polygons from Lines

Now that you have created a line feature class, you are able to make polygons from it. The process is a little convoluted and certainly deserves a line or two in your Fast Facts File.

____ 12. Restart ArcCatalog (not just the Catalog Tree in ArcMap but the entire program). Open ArcToolbox. Expand the following: Data Management Tools > Features, and then pounce on Feature to Polygon. Peruse the Help. For the Input Features text box, using the browse icon, navigate to the TextToFeature_Lines feature class entry and click it so it appears in the Input Features text area. Change the name of the Output feature class to TextToFeature_Polygons in the path

___IGIS-Arc_YourInitials\TextToFeature

Click OK. (You may get a rude shock in the form of an admonition. If so, close ArcMap and try again. If not, just proceed with the next step. See the discussion immediately below to understand why ArcGIS sometimes refuses perfectly reasonable requests.)

The need to modify a geographic data set when it is being used by another program crops up frequently and is usually frustrating. An error message you will sometimes encounter is “Cannot acquire a schema lock because of an existing lock . . .” How you correct this depends on circumstances. If you have an extensive map up and you don’t want to remove a data set from it, you can easily save the entire map, with all its settings, make the modifications to the data set, and then reload (Open) the original map with the ...