Turn on GRASS GIS
At 1. Set GRSSS GIS database directory. You can leave it where it is. Or if you want your GRASS GIS work to be in the same directory with other GIS work, choose a new one.
At 2. Select GRASS location. This is to create a folder for your work. For the first time, select New. At Project location, type a name for the folder such as GEOG454. Click Next. Choose Read projection and datum terms from a georeferenced data file. Click Next. Use Browse, navigate to your folder and choose two_counties . Open. Click Next. Click Finish. A question pops up “Do you want to import two_counties into newly created location?” Choose Yes.
At 3. Select GRASS Mapset. Again, this is to create a subfolder under folder GEOG454. You see a subfolder called PERMENANT. This is a folder where files cannot be changed except the file creator. You also want to create some working subfolders where files can be changed. Choose New. Enter a name such as Intro at Enter name for new mapset. OK.
Make sure GEOG454 and Intro are highlighted. Click Start GRASS session.
At a new session, start GRASS GIS. At Step 2, choose GEOG454, at Step 3, choose Intro. Click Start GRASS session.
You should see a Layer Manager window and a Map Displayer window.
Within the Layer Manager window, got to File-Map display-Add vector. In the dialogue window, from the Name of vector maps, choose two_counties. OK. Close. You should see the map on Map displayer window.
Right click the name of the layer, select Show attribute data. You can see the data table associated with the layer. Close the table.
Right click the name of the layer, select Properties. In the next window, select Colors. Click the Feature colors and select a color. Apply.
Within Map display window, try to use some functions such as Zoom, Pan, etc.
Go to File-Import vector data-Simplified vector import with reprojection. Use Browse to navigate to your folder to select State_IL. Make sure Add imported layer into layer tree is checked. Import. Close.
Within Map display window, click Select features. A small window pops up. Click Madison and St. Clair counties. You will see that they appear in the Select features window. Click Create a new map. You will see that in Layers of the Layer Manager window, a mew map occurs with the two counties.
Go to File-Export vector map-Common export formats. In the next dialogue window, at Name of input vector map to export, choose State_IL_seletion. At Name of output ORG datasource, use Browse to navigate to your folder and save the file as two_counties_GRASS. Run. Close.
Right click State_IL_seletion and choose Remove. Also remove two_counties.
Go to File-Map display-Add vector. In the dialogue window, from the Name of vector map, you can see two_counties is still within PERMENANT folder while State_IL_seletion is within Intro folder. Removing a layer only removes it from the map display window. The layer is still within a folder.
Within Layer Manager window select Data tab at the bottom of the window. Within Intro folder, select State_IL and right click and choose Delete. Also delete State_IL_seletion. Close GRASS GIS.