On 02/03/2012 06:51 AM, Chuck Young wrote: > I have MfrSID raster layer and two Tiger file vector layers. The image > file is for the north half of the county and the vector files (roads and > water) cover the entire county. I have imported them all into the > SpatiaLite database. What I need to do is trim off the data that is > outside the area I need to work with. Is there a method to select the area > I want to keep or the area I want to delete, and remove the unwanted > portions. I know I can go to each entity and break it and delete the > portion that is not needed but there are thousands of entities and this > would take a lot of time. > > Thanks! > > Chuck >
Chuck, Did you want to cut just vectors or also rasters? The method is slightly different for each of those. The basic approach is to create a vector layer that serves as your mask; this can be a simple box (the is a plugin to make a perfect box if you don't want to draw by hand). Step 2 is to clip your other layers using the mask layer. Vector->Geometry Management->Clip Raster->Extraction->Clipper (This is GDAL Translate underneath) If you have multiple layers to do and want to automate that might take a little python or some command line with GDAL/OGR. An alternate method is to use the selection tool (Rectangle), once you have the data selected you want to keep, do a "save selection as" to create a new file of just the selection. I don't think there's a plugin to just do all this for a stack of layers (sounds like a good idea), we could all it cookie cutter... Thanks, Alex _______________________________________________ Qgis-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-user
