# How do I restrict range and domain for 3D functions?

Hugo shared this question 2 years ago

Hello fellow graphers,

I am new to geogebra 3D graphing and I am using it for an essay to explore the accessible volume of a dog in a enclosed area tethered to a pole in the middle. I vary the distance, height of the dogs jump, height of the wall etc.

I was wondering if I could restrict the domain and range for the walls of the fence. On the link, I have set the walls as x=d, x=-d, y=d, y=-d (d is distance from the middle) but it looks really confusing if you don't restrict the functions. Essentially, I wanted to restrict these walls to only be positive z axis and the walls to not intersect eachother (to make it look like an enclosed fence area box) . I also want them to have a certain height (h) that I can vary as well. Please help!

1

You could just draw polygons as walls.

wall1=Polygon((-d,-d,0),(d,-d,0),(d,-d,h),(-d,-d,h),(-d,-d,0))

wall2=Polygon((-d,-d,0),(-d,d,0),(-d,d,h),(-d,-d,h),(-d,-d,0))

etc.

For whatever computations you want to do with the walls, you might still want to define and use the whole planes, just hide them.

1

Or surfaces might be more comfortable:

wall1=Surface(r,-d,s,r,-d,d,s,0,h)

wall2=Surface(-d,r,s,r,-d,d,s,0,h)

etc.

5

Hello,