topic Re: Find lowest value over multiple partitions in a list in FlexSim Forum

Find lowest value over multiple partitions in a list

sander_d_dejong — Thu, 27 Mar 2025 15:19:30 GMT

[ FlexSim 24.0.8 ]

Hellow,

I wanted to query over multiple partition in a list but that unfortunately not possible. Good idea for improvement imho.

Due to various reasons it still better for me to look in multiple partitions than it is to rewrite my model.

In the model I’ve build parcels arrive and are allocated to storage 1,2,3,4. They have a tonnage and a grade (1 or 2). I need to pull the earliest entry (FIFO) of a grade (for example grade 1). But I need to determine what partition has the earliest entry per grade in order to access the right partition.

All I can think of is make a query per partition in a custom code. Put those values in an array and then loop through it to find the lowest value.

Is there a better/easier way to do this?

Re: Find lowest value over multiple partitions in a list

joerg_vogel_HsH — Thu, 27 Mar 2025 16:50:11 GMT

@Sander, a global list is a node structure in model tree. You can evaluate this structure to get references to all partitions. Knowing this you can query each partition by ORDER Clause. Then it is up to you if you order an array, a table or a list to get the lowest value.

https://answers.flexsim.com/answers/64417/view.html

Re: Find lowest value over multiple partitions in a list

sander_d_dejong — Fri, 28 Mar 2025 12:20:37 GMT

Hi @Joerg Vogel ,

Ive tried to understand and implement your comment. unsuccesfull atm.
Ive added the test file. I dont understand how i would go from the partition id to query a partition and get a specific value (label) that i can compare. Could you elaborate please?

(Didnt know the evaluate part, that will be usefull in the future anyhow. thank you.)

Test_list_partition.fsm

Re: Find lowest value over multiple partitions in a list

joerg_vogel_HsH — Fri, 28 Mar 2025 14:11:44 GMT

test-list-partition-jv.fsm

Here I get access to the treenodes of a global List object to get partition IDs and pushTime values of each first entry of a list partition. It is just the source code without any assignment to token labels of any kind.

Re: Find lowest value over multiple partitions in a list

sander_d_dejong — Fri, 28 Mar 2025 15:27:29 GMT

Thanks again @Joerg Vogel. very helpfull!

I kept getting errors from search in the list. I found out that my model creates a partition 0 with nothing in it. and query this partition will throw the code.

After some digging i found the culprit

Table("Storage_levels")[1][1] = Table.query("SELECT SUM(Tonnage) FROM List1.1")[1][1];test-list-partition-jv-S.fsm

So to say it does mess some stuff up in my model. Any ideas on how to elimite this partition 0?

Re: Find lowest value over multiple partitions in a list

joerg_vogel_HsH — Fri, 28 Mar 2025 15:31:00 GMT

@Sander, a partition of 0 is a list without any partition at all. You must have assigned somewhere this value as a partition value. I think that is something you must find out yourself.

Re: Find lowest value over multiple partitions in a list

sander_d_dejong — Fri, 28 Mar 2025 15:37:12 GMT

Yeah my thoughts as well but I havnt assigned it anywhere.

check the file in my last post, i added the tabel.query code to the test model and it creates the 0 partition as well.

By your explaination on the treenodes i can rewrite some code to avoid the tabel.query but it looks like bug to me

Re: Find lowest value over multiple partitions in a list

joerg_vogel_HsH — Sat, 29 Mar 2025 19:31:02 GMT

@Sander, I think you got to a point where you can start a new logic approach. You can push oldest values additionally to a different list. Whenever you pull your oldest value, then you update this additional list by second oldest partitioned list value. Then you are not depending on evaluating tree node structures to override partition lists mechanisms anymore. On the other hand, why do use partitioned lists on first place, if you are still depend on to query all entries. Partitioned lists don’t make sense in this environment. A partition is useful if you query values very often by a special key.