topic Re: Finding the sum of split.index in ArcGIS CityEngine Questions

Finding the sum of split.index

maziaryousefi — Sat, 05 Apr 2025 17:44:52 GMT

Hello everyone. Is there a way to get the sum of the numbers generated by the division command using split.index? For example, we have a 5-story building and if we use the split.index command, the floors start from zero and finally the 5th floor receives the number 4 and the sum is 10, that is, 0+1+2+3+4 = 10

Re: Finding the sum of split.index

JonasObertuefer — Mon, 07 Apr 2025 06:56:56 GMT

Hi @maziaryousefi,

I believe split.total shape attribute is what you are looking for. Let's say you split your mass into three pieces, then split.index is 0,1,2 and split.total is 3.

See also split shape attribute in the CGA reference.

Cheers
Jonas

Re: Finding the sum of split.index

desert — Tue, 08 Apr 2025 08:48:33 GMT

I'm curious whether your goal is simply to compute the sum of split.index values,
or if you also want to pass that sum into other rules for further use.

If your goal is just to calculate the sum, you can use the formula "(split.total - 1) * split.total / 2"

If you'd like to pass the calculated value to other rules and use it there, you can write it like this:

attr unitHeight = 2 // Height of each split section @StartRule Lot --> extrude(10) // Give height to the lot split(y){ ~unitHeight : Section }* // Split along Y into equal parts // Use 'with' to define sum_n as the sum of split.index values Section with ( sum_n := (split.total - 1) * split.total / 2 ) --> case split.index == 0 : Something_A(sum_n) .. ... .... else : Something_Else(sum_n)

There may be various ways to approach this, so please take this as a reference only.

Re: Finding the sum of split.index

maziaryousefi — Thu, 10 Apr 2025 18:14:45 GMT

Thanks for your answer - I want to get the total electricity consumption of the floors and then display it in the report panel at the top of the building. I used the same method as you but it gives the wrong result. I think I need to find a way to associate the amount of electricity consumed by each floor with numerical indices split.index via the set command. If you have any ideas on this, I would be happy to hear it.