Rotating geometries
Among the many functions that PostGIS provides, geometry manipulation is a very powerful addition. In this recipe, we will explore a simple example of using the ST_Rotate function to rotate geometries. We will use a function from the Improving proximity filtering with KNN – advanced recipe to calculate our rotation values.
Getting ready
ST_Rotate has a few variants: ST_RotateX, ST_RotateY, and ST_RotateZ, with the ST_Rotate function serving as an alias for ST_RotateZ. Thus, for two-dimensional cases, ST_Rotate is a typical use case.
In the Improving proximity filtering with KNN – advanced recipe, our function calculated the angle to the nearest road from a building's centroid or address point. We can symbolize that building's point according to that rotation factor as a square symbol but, more interestingly, we can explicitly build the area of that footprint in real space and rotate it to match our calculated rotation angle.
How to do it...
Recall our function from the Improving...
