How to divide a set of numbers into 2 equal sum groups

I have a set of data. example
A=1, b=2,c=3, d=4,e=5,f=6,g=7.
I want to divide into 2 groups so that the sum of both groups are as equal as possible

Marvin..thanks for ur response. I have attached a file and perhaps you could try out ur idea and get back to me with ur methodology via an example, again thanks and i do appreciate

Thanks Marvin. I will give it a try this weekend to see if i understand. thanks so much for ur help,

Try this one:

Thanks Marvin. I found a excel solver method essentially creating 2 buckets which willbe either1 or 0 for each line item and put some constraints to minimize the difference between the buckets, and it works fine; think this approach is more intuitive and will help my team offshore het going quickly
thanks all the same, really appreciate ur help

This solution was tested with 100 random numbers (see attachment). It completed the problem in under 1 second and a single pass of the numbers.

ASSUMPTION:This solution assumes that the resulting 2 groups of numbers must be equal in sum value BUT it does not assume that the groups must have equal number of members. Since the orginal requirements does not indicate groups have to have same number of members.
This solution also assumes it's OK to re-sort the numbers.

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I've set up a Solver solution in sheet "LDB2290_1 reserve". I changed the setup of the object function and simplified the constraints a bit. I've also changed the Solver option by ticking the box "Asume Non-Negative" and increased the max time to 200 seconds.

Have a look and see if this fits your need.

If speed is your main concern stick to nimrod's solution because Solver realy took time in solving this problem. Perhaps a futher triming of options may increase Solver's speed but in no way it will match

It completed the problem in under 1 second and a single pass of the numbers.

nimrod's result.

HTH

Alf

Hi Nimrod,

thanks for the above. Is there a way to do the same, but such that the two groups would:

1. Sum to the same total (or close to it)
2. The groups would be rankes, meaning Group A would be values Min(data) up to X, and Group B would be X+1 up to Max(data).
3. Could this be done for more than one group. i.e. segment three groups as above, each summing to a third of the total sum, or equvalently, each summing to the same number?

Thanks for any help on this!

Originally Posted by nimrod

This solution was tested with 100 random numbers (see attachment). It completed the problem in under 1 second and a single pass of the numbers.

ASSUMPTION:This solution assumes that the resulting 2 groups of numbers must be equal in sum value BUT it does not assume that the groups must have equal number of members. Since the orginal requirements does not indicate groups have to have same number of members.
This solution also assumes it's OK to re-sort the numbers.

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Hello. I am looking at your excel sheet and it works perfect for my purposes, however, I was wondering what would be involved to increase the number of groups from 2 to say 4 or 6? I am not good with the code, but looking at it and it's assumption of half the data, I would assume it would take lot's of work to make it work with any other number of sets correct?