Controls if and how line strings and complex chains should be weeded. If WEED is set to a positive non-zero value, the vertices are weeded according to the following logic: The area of the triangle defined by three following vertices are calculated. If the area is less than the WEED size, the middle vertex is deleted. This is done for all vertices in the line string/complex chain. If COPY is TRUE, the copy will be weeded, otherwise it is the original element. The default value is zero (no weeding). (INIT)