added some screen out put for the current.

also implemented the Ic_4 current.

current 2 and 4 give reasonable results. 1 and 3 do not work yet (expected it to be the other way arround)
All current functions are producing reasonable results. There is only a minus sign to fix.

validation is also needed
start add a simple small piece of code that is gonna check if the interpolation function does wat it has to do