[R] Secant Method Convergence (Method to replicate Excel XIRR/IRR)

Hi, I am new to R, and as a first exercise, I decided to try to implement an XIRR function using the secant method. I did a quick search and saw another posting that used the Bisection method but wanted to see if it was possible using the secant method. I would input a Cash Flow and Date vect

Re: [R] Secant Method Convergence (Method to replicate Excel XIRR/IRR)

--- From: Ravi Varadhan [mailto:rvarad...@jhmi.edu] Sent: Wednesday, August 25, 2010 7:24 PM To: Adrian Ng Cc: r-help@r-project.org Subject: RE: [R] Secant Method Convergence (Method to replicate Excel XIRR/IRR) The secant method converges just fine. Your problem might have occurred due to improper

[R] Writing My Own Function to Use With aggregate

Dear R-Users, I have been using R for about 1 week and recently learned about the Aggregate function, and from reading online it seems like it is comparable to a SQL group by to perform summary functions. I am looking to do a summary function, such as SUM/MIN, but instead of these basic functi