Creating Spatial Feature Classes Based on Proximity, Overlay, and Attributes - Introducing Geographic Information Systems with ArcGIS - page 448

need to supply the rest. Since our Shape_Area is in square meters and our cost is in hectares,
calculate SITE_COST as
Shape_Area / 10000 * COST_HA
9. Run statistics on SITE_COST. To the nearest dollar, what is the cost of the average site?
____________
Considering the Site Eccentricity Criterion
We have one more selection to perform. Recall that the site eccentricity may not be more than 4.6 unless
the total area of the polygon is greater than 7000 square meters.
10. Add another field to the table of Sites_D. Name it Eccentricity. Since the number will contain
decimal places and we are not sure of its range, specify the Type as Float. Click OK.
11. Right-click the Eccentricity column head; pick Field Calculator. Ignore the warning. Write the
expression you need to use in the following blank: ___________________________________. Put
the expression in the Field Calculator window, then check it against Figure 7-25. When you have
it right, Click OK.
The Attributes of Sites_D window will have eccentricities ranging from just over 4 to about 6 and a half.
12. Clear any selected records or polygons. Use Analysis Tools > Extract > Select to apply the
criterion. Write the SQL Expression that will let you use Sites_D to make a feature class called
Final_NEW_Sites, that satisfies this additional requirement. ______________________________
______________. Wait to look at Figure 7-26 until you have written your expression. Select the
proper polygons with the Select tool. How many are there? ____
FIGURE 7-25 Wildcat eccentricity calculation