[R] Uniroot and Newton-Raphson Anomaly

I have the following function for which I need to find the root of a: f <- function(R,a,c,q) sum((1 - (1-R)^a)^(1/a)) - c * q To give context for the problem, this is a psychometric issue where R is a vector denoting the percentage of students scoring correct on test item i in class j, c is the p

Re: [R] Uniroot and Newton-Raphson Anomaly

n...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of Doran, Harold Sent: Monday, March 16, 2009 10:34 AM To: r-help@r-project.org Subject: [R] Uniroot and Newton-Raphson Anomaly I have the following function for which I need to find the root of a: f <- function(R,a,c,q) sum((1 - (1-R)^