On Dec 6, 2007 3:26 PM, marciarr <[EMAIL PROTECTED]> wrote: > > Hello R users, > I have been looking through Help files and Nabble list for the answers for > these simple questions, but it seems to be fruitless. > 1- in a data frame with two columns, x and y, how do I get the corresponding > value of x to, let's say, the minimum value of the y column (min (data$y)) ?
In the builtin Formaldehyde data frame find the value of carb (first column) which corresponds to the least value of optden (second column): with(Formaldehyde, carb[which.min(optden)]) > 2- how do I solve a simple equation? Considering the equation y= exp(-x)^12, > I would like to find the values of x for, for example, y=0.01, so > exp(-x)^12=0.01. How do I do that using R? > I know those a probably very, very simple questions, but for which I do not > seem to find the answer. Search between 0 and 1 for the root of the indicated function: uniroot(function(x) 0.1 - exp(-x)^12, 0:1) ______________________________________________ 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.
