Dear all, I have a question concerning the mesh definition with RectangleMesh: I define my mesh as a Rectangle mesh, with quadrilaterals as: hor_mesh = RectangleMesh(Nx, Ny, 10.0, 1.0, quadrilateral=True). As my functions are only (x,t) dependent, I'd like to get only one element in y, i.e. Ny=1. However I noticed that if I set Ny=1, then the x-coordinates are swapped from 10.0 to 0.0 . Basically, I obtain hor_mesh.coordinates.dat.data[:,0] = [10.0 10.0 9.9 9.9 ...... 0.0] instead of hor_mesh.coordinates.dat.data[:,0] = [0.0 0.0 0.1 0.1 ........ 10.0] (that I obtain for Ny>1) Can someone explain me what happens there ? Is there a way to avoid that ? And if I use the integral on ds(1), will it be at x=0 of x=10 in that case? The reason why I want to understand this is because I apply a change of coordinate in some part of the domain (let's say for x<L<Lx) and the coordinate transform does not give the right result for Ny=1 (while it does for Ny>1). Thanks in advance for your help, Floriane