I have a file with buildings as polygons and am trying so simplify and convert these to centroids. I have Disolved and added a buffer. But after that I am stuck:
A) I want to add a attribute where polygons larger than 400 m2 are categorised as "4", polygons between 400 and 200 are categorised as "3", and so on. How do I do this? (The AttributeMapper almost does this, but as far as I can see it does not work with operators, only hard numbers.)
B) In the next step I want to check if any smaller polygons are touching a bigger one. Eg. If a polygon with the size 1,2 or 3 touches a 4 they get dropped. Same thing if a 1 or 2 touches a 3, and so on. Which transformers would accomplish this?
C) At the end of it all I want to measure the angle between the first and second corner in each polygon and ad this as a rotation attribute. What is the best method to do this?
Sorry for the barrage of questions...
