求助：GRID模块中的带有括号的命令怎么用？如HILLSHADE

在GRID模块中有些函数命令，如： <BR>HILLSHADE <BR>USAGE:<I> HILLSHADE (<grid>, {azimuth}, {altitude}, <BR>{ALL | SHADE | SHADOW}, {z_factor}) <BR>FOCALRANGE <BR>USAGE:<*> FOCALRANGE(<grid>, <RECTANGLE>, <width>, <height>, {DATA | NODATA}) <BR>命令中的这些*号,还有圆括号怎么用啊？最好给一条具体的例子让我看看。谢过了。。 <img src="images/post/smile/dvbbs/em02.gif" /><img src="images/post/smile/dvbbs/em02.gif" /><img src="images/post/smile/dvbbs/em02.gif" />

<STRONG>Script example<BR><BR></STRONG><PRE><I># HillShade_sample.py
# Description: Computes hillshade values for a raster surface.
# Requirements: None
# Author: ESRI
# Date: 12/01/03

# Import system modules</I>
import sys, string, os, win32com.client

<I># Create the Geoprocessor object</I>
gp = win32com.client.Dispatch("esriGeoprocessing.GpDispatch.1")

try:
<I># Set local variables</I>
    InRaster = "C:/data/dem"
    OutRaster = "C:/data/hillshade"
    InAzimuth = "325"
    InAltitude = "50"

<I># Check out ArcGIS Spatial Analyst extension license</I>
    gp.CheckOutExtension("Spatial")

<I># Process: HillShade</I>
    gp.HillShade_sa(InRaster, OutRaster, InAzimuth, InAltitude)

except:
<I># Print error message if an error occurs</I>
    gp.GetMessages()</PRE><PRE> </PRE><PRE> </PRE>