Hello Jean.
The scale of the mesh next to the x and y axes is not correct,
since it is half the unit on each side.
Easy to fix, Carlos ... like this.
It's normal the [XY axes] don't split exactly ½ way in
between the grid. Grid is 9 pixels, the native QuickPlot
grid spacing is 41 pixels. Handles will give either 40/41
but not 40.5. However, far superior to Mathcad/Mathsoft.
2D Plot Discrete over Grid.sm (16.54 KiB) downloaded 482 time(s).