dpender wrote: > > Hi, > > I am using the uniroot function in order to carry out a bivariate Monte > Carlo simulation using the logistics model. > > I have defined the function as: > > BV.FV <- function(x,y,a,A) > (((x^(-a^-1)+y^(-a^-1))^(a-1))*(y^(a-1/a))*(exp(-((1^(-a^-1)+y^(-a^-1))^a)+y^-1)))-A > > and the procedure is as follows: > > Randomly generate values of A~(0,1), y0 = -(lnA)^-1 > > Where: A=Pr{X<xi|Y=yi-1} and a is the dependency between X and y (0.703) > > Use y0 to determine x where x = x(i) and y = y0(i-1) in the above > equation. > > Unfortunately when the randomly defined A gets to approximately 0.46 the > intervals I provide no longer have the opposite signs (both -ve). >
Try curve(BV.FV(x,y=y0,a=.703,A=.7),from=1,to=10) for different values of a, A and y0. I have a feeling that your function or something else is not quite correct. Berend -- View this message in context: http://r.789695.n4.nabble.com/uniroot-tp3260090p3260438.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.