A formula for IRR

[salvomic]

a dirty solution toward the final version...

This program (Home HPPL) recall a #CAS function and present it in Terminal (so when there is a series of cash flows that the "Home" part doesn't handle, the result(s) appear(s) on terminal, while program gives error), and, at the same point, it's possible to edit the list (flows).

Welcome for better solutions!

Code:


EXPORT IRR()
// Thanks Cyrille, Akmon, Dale, salvomic
// cash flow in {flow} list
BEGIN
local mesg;
EDITLIST(flows);
mesg:= irr2();
PRINT(mesg);
RETURN fsolve(ΣLIST(MAKELIST((flows(I)/X^(I-1)),I,1,SIZE(flows))),X)-1;
END;

#cas
irr2():=
BEGIN
fsolve(ΣLIST(MAKELIST((flows(I)/X^(I-1)),I,1,SIZE(flows))),X)-1;
END;
#end

EDIT: If I use RETURN to return directly the result of #CAS function I get something like:
program({},{},[-1.0171... 0.138654...])
a very "ugly" output!