Recently I came across the problem of amortizing swaps. This is an agreement, where fixed payments and floating payments (e.g. 3-months LIBOR + spread) are exchanged based on a notional that is reduced (=amortized) according to a fixed schedule.
Are there good references for a precise formula?
Are there simple formulas, maybe approximations to derive a fair swap rate for the amortizing swap from the plain vanilla swap?
Are there calculators online or on Bloomberg for such agreements?