Hi Renato, In order to use the VECTOR command you need to have a grid, but that grid could be quite simple. It depends a bit on what you're plotting this on. Are you overlaying it on some plot? One idea is to just draw an arrow, with PLOT/VS/OVER commands - would that do what you want? Here's a simple little example to show you the idea. If this isn't what you're thinking about write back with more information about what you want to do. yes? use etopo60You could define the points to draw this in whatever location and direction you want. This is a very non-general way to do this. Ferret can take care of the length and rotation of the vector automatically, but you would need to have vector components on a grid. Ansley Renato Parkinson Martins wrote: Dear all, |