- Graphically create and edit geometric data, as with a CAD program
- Import Shapefiles and OpenStreetMap data
- Use raster images as background and a CAD drawing as an overlay
- Transform coordinates based on the Proj4 library.
- Color polygons based on user data values using either discrete intervals or gradients
- Allocate point data to user specified buffers for points, polygons and multilines (e.g. find all gas stations within 1 mile of a highway)
- Allocate point data to polygons. (e.g. assign structures to hydrological basins)
- Allocate polygon data to other polygons. (e.g. allocate population data by census block to political boundaries)
- Create thiessen polygons (e.g. for all hospitals within a state, define the areas closest to each hospital)
- Create data contours (e.g. create lines of equal ground elevation based on a set of elevation points)
- Create contour polygons (e.g. define the area where average rainfall exceeds a selected value based on weather station data)
- Calculate the area and perimeter of irregular polygons, including exclusion polygons (i.e. holes)
- Data is stored in an open database allowing manipulation by other software
Even if you don't yet need these easy to use spatial analysis operations, TdhGIS makes a very good Shapefile viewer and editor!