You have to install it from CRAN before you can load it into your session. ____________________________________________________________________
Ravi Varadhan, Ph.D. Assistant Professor, Division of Geriatric Medicine and Gerontology School of Medicine Johns Hopkins University Ph. (410) 502-2619 email: rvarad...@jhmi.edu ----- Original Message ----- From: Shaoqiong Zhao <zh...@uwm.edu> Date: Thursday, March 11, 2010 9:00 pm Subject: Re: [R] help about solving two equations To: Ravi Varadhan <rvarad...@jhmi.edu> Cc: r-help@r-project.org > Hello Professor Ravi, > > I tried to load BB into R, but I got the following message: > library("BB") > Error in library("BB") : there is no package called 'BB' > > library(BB) > Error in library(BB) : there is no package called 'BB' > > Can you tell me why? > > Thanks a lot. > > Annie > > > ----- Original Message ----- > From: "Ravi Varadhan" <rvarad...@jhmi.edu> > To: "Shaoqiong Zhao" <zh...@uwm.edu> > Cc: r-help@r-project.org > Sent: Wednesday, March 10, 2010 9:03:25 PM GMT -06:00 US/Canada Central > Subject: Re: [R] help about solving two equations > > Here is how you can solve: > > fn <- function(x, s){ > f <- rep(NA, length(x)) > f[1] <- digamma(x[1]) - digamma(x[1]+x[2]) - s[1] > f[2] <- digamma(x[2]) - digamma(x[1]+x[2]) - s[2] > f > } > > require(BB) # load this package for the nonlinear solver > > s <- c(-2, -4) # one row of s1 and s2 > > ans <- dfsane(par=c(1,1), fn=fn, s=s) > > ans$par # solutions for p and q > > You can then loop through for each row of s1 and s2 and solve it to > get corresponding p and q. > > Ravi. > ____________________________________________________________________ > > Ravi Varadhan, Ph.D. > Assistant Professor, > Division of Geriatric Medicine and Gerontology > School of Medicine > Johns Hopkins University > > Ph. (410) 502-2619 > email: rvarad...@jhmi.edu > > > ----- Original Message ----- > From: Shaoqiong Zhao <zh...@uwm.edu> > Date: Wednesday, March 10, 2010 8:19 pm > Subject: [R] help about solving two equations > To: r-help@r-project.org > > > > I have two matrix s1 and s2, each of them is 1000*1. > > and I have two equations: > > digamma(p)-digamma(p+q)=s1, > > digamma(q)-digamma(p+q)=s2, > > and I want to sovle these two equations to get the value of x and > y, > > which are also two 1000*1 matrices. > > > > I write a program like this: > > > > f <- function(x) { > > p<- x[1]; q <- x[2]; > > ((digamma(p)-digamma(p+q)-s1[2,]) )^2 > > +((digamma(q)-digamma(p+q)-s2[2,]) )^2 > > } > > s <- 1:10/10 > > g <- expand.grid(p = s, q = s) > > idx <- which.min(apply(g, 1, f)) > > idx > > g[idx,] > > > > I am not sure if this is correct and also this can only solve one > > > row. How to get the whole 1000 rows of p and q? > > > > Thanks. > > > > Annie > > > > ______________________________________________ > > R-help@r-project.org mailing list > > > > PLEASE do read the posting guide > > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.