求助:AE实现用不规则多边形切割栅格数据

我现在要用一个不规则多边形切割栅格数据,并对新生成的栅格数据进行计算统计,请问怎样用AE实现第一步,即,怎样实现由不规则多边形切割栅格数据<BR>

<P>你在arcgis desktopo的帮助里查看clipping, rasters</P>
<P>有说明 </P>ArcObjects example
<P>'Function Clip(ByVal GeoDataset As esriGeoDatabase.IGeoDataset, _' ByVal Rectangle As esriGeometry.IEnvelope) _' As esriGeoDatabase.IGeoDataset' Member of esriGeoAnalyst.ITransformationOpDim pTransformationOp As ITransformationOpSet pTransformationOp = New RasterTransformationOp' Get rasterDim pRas01 As IRasterSet pRas01 = getRasterFromDiskFunction("c:\data\myRaster")' Declare an envelope objectDim pEnvelope As IEnvelope' Create an envelopeSet pEnvelope = New EnvelopepEnvelope.PutCoords 1, 1, 3, 3Dim pGeoDS As IGeoDatasetSet pGeoDS = pTransformationOp.Clip(pRas01, pEnvelope)<BR></P>

<P>这不是只有用矩形切割吗?那用不规则的多边形怎么切呢?</P>