Computes the Internal Rate of Return (IRR) of the given cash flows. There may be multiple valid
IRR results. NaN and infinite results are filtered out. Results less than -100% are also filtered
out, since they are unreasonable as IRRs --- investment would turn negative in the next period
after a period with a positive balance, and the negative balance would generate positive return
in that period.
Computes the Internal Rate of Return (IRR) of the given cash flows. There may be multiple valid IRR results. NaN and infinite results are filtered out. Results less than -100% are also filtered out, since they are unreasonable as IRRs --- investment would turn negative in the next period after a period with a positive balance, and the negative balance would generate positive return in that period.