... (shortcut key Alt+1) and Mark second point (shortcut key Alt +2) . 53 Chapter 4 Graphical user interface The goal of the graphical user interface design is to create an appropriate environment as ... to correspond to the actual surface.An example of printed isolines is in figures 2. 4.2b, 2. 4.2c and 2. 4.2d.4 .2. 3.6 Blanking grid outside the boundaryThe function Blank grid outside boundary ... approximation 20 0 0 ,2 20 0 Smooth interpolation 500 0 ,2 1 1 Normal interpolation 500 0,5 1 1 Sharp interpolation 500 20 0,7 1 1 LES interpolation 1000 -0,5 1 1 Digital model of terrain 1000 20 0,7...