I am calling the uniroot function from inside another function using these lines (last two lines of the function) :
d <- uniroot(k, c(.001, 250), tol=.05) return(d$root) The problem is that on occasion there's a problem with the values I'm passing to uniroot. In those instances uniroot stops and sends a message that it can't calculate the root because f.upper * f.lower is greater than zero. All I'd like to do in those cases is be able to set the return value of my calling function "return(d$root)" to .0001. But I'm not sure how to pull that off. I tried a few modifications to uniroot but so far no luck. For convenience, the uniroot function is shown below: uniroot <- function (f, interval, ..., lower = min(interval), upper = max(interval), f.lower = f(lower, ...), f.upper = f(upper, ...), tol = .Machine$double.eps^0.25, maxiter = 1000) { if (!missing(interval) && length(interval) != 2L) stop("'interval' must be a vector of length 2") if (!is.numeric(lower) || !is.numeric(upper) || lower >= upper) stop("lower < upper is not fulfilled") if (is.na(f.lower)) stop("f.lower = f(lower) is NA") if (is.na(f.upper)) stop("f.upper = f(upper) is NA") if (f.lower * f.upper > 0) stop("f.up * f.down > 0") val <- .Internal(zeroin2(function(arg) f(arg, ...), lower, upper, f.lower, f.upper, tol, as.integer(maxiter))) iter <- as.integer(val[2L]) if (iter < 0) { warning("_NOT_ converged in ", maxiter, " iterations") iter <- maxiter } list(root = val[1L], f.root = f(val[1L], ...), iter = iter, estim.prec = val[3L]) } -- View this message in context: http://r.789695.n4.nabble.com/How-do-I-modify-uniroot-function-to-return-0001-if-error-tp3424092p3424092.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.