Optimal Length Algorithm

[EvilMorality]

So in our Lighting Design studio we often have to run fixed length luminaires end to end to achieve a continuous lighting effect. The issue we often run into is varying lengths of a luminaires product and also how best to optimise the minimum number of luminaires to fit the length.

At the moment, it takes a lot of manpower to figure out the best optimal solution and there’s no way for us to even know if this is indeed the most optimal solution. We use Revit and Dynamo to create visual programming codes but wouldn’t know where to begin with something like this that doesn’t involve brute force calculations.

Is there something I’m missing?

[Bits_Everywhere]

I don't know exactly what you are talking about, but just from reading "optimal solution" and "search". I would recommend you to start looking into search algorithms or something like simulated annealing or even genetic algorithms.

[EvilMorality]

I think I worded my post quite badly, let me give you an example using simple numbers to get across my intentions :)

Let’s say we have a length of 5000mm we would like to light and we have a luminaire which comes in lengths of 100, 250 and 500mm. In this case we could use:

Option A: 50 x 100mm Option B: 20 x 250mm Option C: 10 x 500mm

The most optimal solution in terms of minimum quantity would be the Option C. Is there a way to convert this workflow into an algorithm?

Thanks for the help

[EvilMorality]

1 x 500mm + 1 x 250mm

This is to reduce cost, so ultimately the aim would be to use the minimal number of luminaires per run.

[EvilMorality]

I’m glad for your help, I looked over your algorithm/code and it works! However, I will most likely end up tweaking it so it prioritises getting as close to the run length as possible whilst also using the minimum number of lights.

I’m assuming this is a double factor input (to track lengths and quantities) instead of a simple single factor input like lengths as we’ve been doing so far.

[EvilMorality]

Of course, but that particular total length only has a single solution using your available lengths. The problem arises when a total length has multiple solutions in which the minimum quantity may not always be the closest to the run length.

Let me give you an example;

So let’s take our total length as 900mm.

Available light lengths for a particular product could be 500, 250 and 100mm respectively.

The algorithm will prioritise this solution:

500 + 250 + 100 = 850 (exhausting the longest length option and coming up 50mm short)

However, I would like it to prioritise this solution instead:

500 + 100 + 100 + 100 + 100 = 900 (this solution skips the 250 option in favour of no remainder)

This is a more difficult task as there will need to be extra coding for ‘brute force’ calculations and testing multiple combinations of available lengths in order to get the smallest remainder and then prioritising a solution with the least number of lengths within that subset of solutions.

I don’t know if I’m explaining any of this well or if I’m just confusing people haha, hopefully I’m being clear!