Using scatter map plots
The main difference between the x and y axes and longitude and latitude is due to the shape of the Earth. As we approach the equator, the vertical meridians are as far away from each other as possible, and as we approach the North and South poles, they are as close as possible to each other. Figure 7.10 shows this:
Figure 7.10 – A map of the Earth, showing longitude and latitude lines
In other words, as we approach the equator, we have a more rectangular shape, because a unit of longitude is close to a unit of latitude. Close to the poles, the proportions are completely different, and the rectangles start to approximate triangles. This is in contrast to a rectangular plane, where a vertical unit of distance corresponds to the same horizontal unit of distance, regardless of where you are on the plane. This assumes a linear scale on both axes, of course. An exception to this is the logarithmic axis, which we covered in Chapter...
