When you have chosen dato t[sub]a[/sub] and latitude b[sub]g[/sub] the angle of sun against horizon is shown obviously only during daytime. The slide t[sub]d[/sub] gives the time by a special table calculation. If it is animated the sun moves in the lightblue field of daylight and the point B[sub]g [/sub]in 3D-Grafics. If you want to observe that you should shut down all animations in the "Grafics"-window. [br]The line of function is [b]no projection of the suns way[/b] to any plane because that would give a singularity if sun is running through zenith.