Hi I am new to grasshopper and need some help. I made these curves and extruded them, but I want them to extrude with a parabolic shape. So I want the bottom to extrude more then the rest towards to middle. Like an arch bridge. I hope I am being clear. I added some art for reference. Thx
could you please provide more info/sketches on what type of end result are you looking for?
Sorry but I’m not able to understanding it from the image 
Im sorry, I hope this explains it. So I made some wavey lines from the contour component. I then extruded those lines all straight down with the same length, which resulted into my second image shown above. In that image all the lines are now about the same length. But I want the lines to gradually extrude more towards the middle from the bottom. So the top of the lines should stay as the second image but the bottom of the lines should extrude more as they get closer to the middle.
The object is supposed to be a roof and the lines have to extrude more in the middle to be structural.
I hope this clears things up. Thx
ok, now I got it 
I think a possible approach might be to create a loft between top-weavy-curves and bottom-as_you_like-weavy curves that you need to draw separately
for instance, here your own “random Z-movement” part is just applied again below (in red), with a different Domain, to create a sort of weavy movement but in direction -Z:
and before being applied to the points, those -Z vectors are summed up together with other -Z vectors based on the distance of each Surface Point to the Surface center-point:
in such a way to get two distinct surfaces, which represent the Top/Bot boundaries on which Contour is generating the Curves to be lofted:
this would generate a final shape -which will for sure need some more tweaks- but might look a bit more like to what you are looking for?
Reddit_Re.gh (20.7 KB)
