The method of pulse signal deinterleaving by planetransformation has a disadvantage of detecting the characteristic lines with manpower.
针对平面变换分选信号方法中人工检测特征曲线的缺点，对平面变换后特征曲线的检测方法进行了研究。
2
Maps (on paper or on the screen) are flat surfaces; they require a transformation from the curved surface of the earth to the flat plane: a map projection.
纸上或屏幕上的地图是平面的；它们需要从地球的曲面向平面进行转换：地图投影。
3
Let's say that in the plane we look at the transformation that does rotation by 90 degrees let's say, counterclockwise.