GRASS Basics - Desktop GIS: Mapping the Planet with Open Source Tools - page 315

Figure C.12: Adding a Column to a GRASS Vector Map
In Figure C.12 , you can see the settings filled out for the name field. If
you wanted to add more columns, you can do so using the same pro-
cess. To create the column(s), click the Create Table button, and then
close the settings dialog box. Now we have a vector map and associated
attribute table ready for digitizing.
Let's take a look at the tools available for digitizing (see Figure C.11 , on
page 324 ) . The first four tools are for refreshing and navigating the map
and by now should be pretty familiar. The first button just redraws the
map. The others allow you to zoom in, out, and pan the map. I need
to point out a key feature of this dialog box: the three wide buttons
below the toolbars represent the buttons on your mouse (yes, you need
a three-button mouse or some way to emulate one). When you select a
tool, the labels on the buttons change to give you a visual cue as to the
function of each mouse button. Get used to looking at the labels; it will
help you as you digitize. If we click the Zoom in by window tool, we see
that the mouse button functions are as follows:
• 1. corner
• 1. corner
• Quit
So, this means we can use buttons 1 or 2 (left or middle) to mark the
first corner of our zoom window. When we click the map with either
button, the button labels in the dialog box change yet again:
• 1. corner
• 2. corner
• Quit