I would do in the opposite manner. Consider the "life (business) after the split". What you are going to miss - technology, money, market, relationships ? And, of course, subtract the amount of the splitting cost. Consider the worst case, and may be that will be result you would get.
Is that acceptable for you ? Is the business going to survive ?
If yes, go in splitting. Better suffer financial losses, but work for your ideas, which eventually would flourish.
If not, apply humility and go for fair and friendly talk with the partner. Remember, at the beginning something made you together.