[R] simple problems

Domenico Vistocco vistocco at unicas.it
Thu Dec 6 22:49:22 CET 2007


marciarr 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$y)) ?
>   
data$x2[data$x1==min(data$x1)]
> 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 there is solve for linear equations, but I do not know if there is
a generic solver for other equations.
You could implement it using a numerical approach (perhaps it is yet in some
package).

domenico



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