# Sorting point IDs by distance to Null

This ICE tree builds an array that holds the point IDs, sorted by their distance from a null:

Now, here’s how to move the “index in sorted array” and the “distance from null” down to per-point data.
(For clarity, I changed the Show Values to show only for tagged points.)

# Simple example of a parametric point cloud

Here’s a simple parametric point cloud that shows the two techniques for using arrays instead of Repeats that I blogged about earlier:

I used this set of parametric equations to get a cylinder point cloud:

x = sin(u)
y = cos(u)
z = v

where

0 <= u <= 2*PI
-2 <= v <= 2

For this exercise, I simply used Build Interpolated Array to build arrays of U and V values, but I probably should use something like the XYZ_Grid_Generator technique described by Daniel Brassard on si-community.

Here’s a version of the ICE tree with some Show Values.

I use the Modulo technique to build an array of the XY values for all points in the cloud.

Then I use the Divide by Scalar technique (the integer result is truncated) to build an array of the Z values.

Finally, I add XY vectors to the Z vectors to get the final point positions.