[求助]急！如何计算一条折线首尾两点与正东方向的夹角

 
<P>小弟初学Arcgis，论文需要想求折线首尾两点连线与正东方向的夹角，请高手帮忙！</P>
<P>谢谢！</P>

<P>arcgis里好象没有直接的工具可以使用，</P>
<P>你可以编写程序，或者使用字段计算器编写脚本来获取，</P>

把下面代码放arcgis里vba宏运行<br>前提是你选中了折线<br><br>Sub Gisempire_lineway()<br>  Dim pDoc As IMxDocument<br>  Dim pMap As IMap<br>  Dim pEnumFeat As IEnumFeature<br>  Dim pFeat As IFeature<br>  <br>  Set pDoc = ThisDocument<br>  Set pMap = pDoc.FocusMap<br>  Set pEnumFeat = pMap.FeatureSelection<br>  Set pFeat = pEnumFeat.Next<br>  Do While (Not pFeat Is Nothing)<br>    If pFeat.Shape.GeometryType = 3 Then<br>      Dim pline As IPolyline<br>      Set pline = pFeat.Shape<br>      Dim iline As iline<br>      Set iline = New Line<br>      iline.FromPoint = pline.FromPoint<br>      iline.ToPoint = pline.ToPoint<br>      Dim dAngle As Double<br>      dAngle = (180 * iline.Angle) / (4 * Atn(1))<br>      If dAngle < 0 Then<br>        dAngle = dAngle + 360<br>      End If<br>      MsgBox dAngle<br>    End If<br>  Set pFeat = pEnumFeat.Next<br>  Loop<br>End Sub<br>

<P>谢谢啦</P>
<P>哈哈</P>