Products of a GIS: Maps and Other Information - Introducing Geographic Information Systems with ArcGIS - page 208

7. While we are at it, let's also make a simple layout of the data and save it as a map named KY_
Streams.mxd in the same folder: Map_Making. Go to Layout View, then click File > Save. Type
in a filename, and click Save again.
8. Click on the New Map File icon, bringing up the New Document window. You should not be
asked to save anything. Go to Data View. Add KY_Streams_spf. shp from
___IGIS-Arc_ YourInitials \Map_Making.
Notice that the KY_Streams data set is drawn all in a single color, with no size differentiation.
Remove the shapefile.
9. Click the New Map File icon, specifying a blank map, and saying no when asked about saving.
You should be in Data View, but go there if you aren't there already. Add KY_Streams_spf.lyr from
___IGIS-Arc_ YourInitials \Map_Making.
Notice that the KY_Streams data set is drawn as you symbolized it.
There is an important caveat to be mentioned here. The layer file does not contain data; it only contains
the instructions as to how the data set is to be drawn.
10. Use Windows Explorer to navigate to the folder
___IGIS-Arc_ YourInitials \Map_Making.
Ask for details of the files listed there. What is the size of:
KY_Streams_spf.shp __________________
KY_Streams_spf.dbf __________________
KY_Streams_spf.lyr __________________
KY_Streams.mxd __________________
The SHP file is the geographic feature data. The DBF holds the attribute data. Together they
constitute more than 60 million bytes. The LYR file, in contrast, occupies a mere 9,000 bytes.
Obviously, the layer file does not contain the KY_Streams data. Also, the map file (mxd) is way
too small to hold the actual data.
11. For a more dramatic illustration that layer files do not contain the data, do the following. In
ArcMap, start a new blank map file without saving the changes to the current file. In ArcCatalog,
click the words Folder Connections and press F5 to refresh the catalog tree. In ArcCatalog,
delete KY_Streams_spf.shp from ___IGIS-Arc_ YourInitials \Map_Making. (You can do this either
with the Delete key or by right-clicking the selection and clicking Delete.)
Now try to preview the Geography of KY_Streams_spf.lyr by clicking its name. What is the
message you get? ___________________________________________________________________
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