glue a set of graphics entities into an Compound.
glue(H) h_agreg=glue(H)
a vector of unique handle.
Only Matplot, Champ, Fec, Grayplot, Polyline, Fac3d, Plot3d, Arc, Rectangle, Segs, Text and Compound are supported
a handle, the handle on the Compound entity.
Given a vector of handles, this function glue the corresponding entities in a single Compound and returns the handle on this new entity.