Public Comment: ODFF: XIRR

Replace existing content with: "Constraints: The size of Values and Dates are equal. Values contains at least one positive and one negative cash flow." And under Semantics: "Values: a series of cash flows. Negative cash flows represent payments given; positive cash flows represent payments received." And: "Guess: If provided, Guess is an estimate of the interest rate to start the iterative computation. If omitted, the value 0.1 (10%) is assumed. The result of XIRR is the rate at which the XNPV() function will return zero with the given cash flows. There is no closed form for XIRR. Implementations may return an approximate solution using an iterative method, in which case the Guess parameter may be used to initialize the iteration. If the implementation is unable to converge on a solution given a particular Guess, it may return an error."