Voxel Grid Sparsity

Problem

Compute the sparsity of a voxel grid.

Sparsity is 1 - occupied / total, where occupied is the number of unique voxels containing points and total is dims[0] * dims[1] * dims[2]. Return the value rounded to 4 decimal places, or 0.0 when total is 0.

Hint

A dense grid has sparsity 0; an empty grid has sparsity 1.

Test cases

case 1

in: [[[0.1,0.1,0.1],[1.5,1.5,1.5]],1,[2,2,2]]

expected: 0.75

case 2

in: [[],1,[4,4,4]]

expected: 1

case 3

in: [[[0,0,0]],1,[1,1,1]]

expected: 0

case 4

in: [[[0.5,0.5,0.5],[1.5,0.5,0.5],[0.5,1.5,0.5],[1.5,1.5,0.5],[0.5,0.5,1.5],[1.5,0.5,1.5],[0.5,1.5,1.5],[1.5,1.5,1.5]],1,[2,2,2]]

expected: 0

Starter codePython

def voxel_sparsity(points, size, dims):
    # Your code here
    pass

4 test cases · run your code against them in the editor