计算子午圈半径M 计算卯酉圈半径N 计算玮圈半径r 计算经线弧长Sm 计算纬线弧长Sn 计算球面梯形面积 计算最大角度变形 计算球面极坐标-calculated Meridian circle radius circle conveniently calculated M N calculation Wei radius circle radius r calculated meridian arc Sm calculated latitude arc

mapcad ,在mapinfo下开发的测量绘图工具-mapcad, in developing measurement mapinfo drawing tools