在Arcgis 10中用Python计算方位角时的语法错误

Question

我正在尝试在ArcGIS 10中用Python计算方位角，但遇到了语法错误。以下是我的代码：

def CalculaAzimuth(Linea):
    Xorigen = linea.firstPoint.Y
    Yorigen = linea.firstPoint.X
    Xfinal = linea.lastPoint.X
    Yfinal = linea.lastPoint.Y
    DeltaX = Xfinal - Xorigen
    DeltaY = Yfinal - Xorigen
    PI = math.pi()
    Azimuth = 4 * PI
    if DeltaX = 0:
        if DeltaY >=0:
            Azimuth = 0
        else:
            Azimuth = 180
    elif DeltaX >0:
        Azimuth = 90 - math.atan( DeltaY / DeltaX ) * 180 / PI
    elif DeltaX <0:
        Azimuth = 270 - math.atan( DeltaY / DeltaX )* 180 / PI

return Azimuth

Answer 1

好的，这里有一个整理过的版本，包含了上面的所有评论，还有一些逻辑上的小改动和变量的清理。请注意，这并不是一个真正的椭球体上的方位角。

def CalculaAzimuth(linea):
    if (hasattr(linea,'type') and linea.type == 'polyline'):
        xf = linea.firstPoint.X
        yf = linea.firstPoint.Y
        xl = linea.lastPoint.X
        yl = linea.lastPoint.Y
        dX = xl - xf
        dY = yl - yf
        PI = math.pi
        Azimuth = 0 #Default case, dX = 0 and dY >= 0
        if dX > 0:
            Azimuth = 90 - math.atan( dY / dX ) * 180 / PI
        elif dX < 0:
            Azimuth = 270 - math.atan( dY / dX )* 180 / PI
        elif dY < 0:
            Azimuth = 180
        return Azimuth
    else:
        return False