Hamid, I have looked in a bit more detail at the possibility of producing a loan calculator for Islamic finance, principally at Musharaka type loans in which the investor is assigned equity in the business. The major difficulty in implementing any sort of calculator in this case is that payments to the investor depend on the profit made by the business and the fraction of the equity in the business the investor has purchased.
The profit is an unknown quantity before the end of any repayment period which is then shared on an agreed basis between the original owner and the investor on the basis of their respective equities. There is no way to predict the payment until the profit for the business is calculated from the books for the period. It is even more complex where the share of equity of the investor is decreased over time by repayment at a rate higher than the investors share of the profit for the same reason that the profit is not a quantity that is necessarily calculable from the nominal value of the business. This makes it impossible to calculate future payments, and the equity and outstanding principal of the loan at a future time in the way one can with a loan with an interest rate. I can derive a sequence of calculations which must be carried out at the end of each repayment period once the profit for that period is available, but this sequence cannot possibly converge to give any future predictable results as each period a new unknown quantity is introduced into the calulation which is independent of any fixed parameters of the calculation. In such a case one would be better maintaining a calculation in a spreadsheet which updates when the profit is available and simply transferring the quantities to the transactions entered into GnuCash. I have not looked at other loan types but they all appear to have a payment calculated in some manner from profits which is an unknown quantity. In the case of Ijara type contracts, the lease schedule of payments appears to be part of the contract and is whatever is agreed between the lessee and the lessor, i.e. ther is no need to calculate it because it is already prespecified in the contract. David Cousens ----- David Cousens -- Sent from: http://gnucash.1415818.n4.nabble.com/GnuCash-Dev-f1435356.html _______________________________________________ gnucash-devel mailing list gnucash-devel@gnucash.org https://lists.gnucash.org/mailman/listinfo/gnucash-devel
