On Sun, Oct 12, 2008 at 7:24 AM, Oliver Bandel <[EMAIL PROTECTED]> wrote: > Hello, > > > I don't understand the description / help-text for the > numericDeriv() function. > > Why is there a new environment used? > > And what is meant with an environment here?
?environment or http://socserv.mcmaster.ca/jfox/Books/Companion/appendix-scope.pdf > Is it similar or the same as a local workspace, > like an environment in functional languages? > > And why is it needed here? > > numericDeriv could just calculate the difference bewtween two > values and divide this difference by the distance (which is one > normally, > but maybe in timeseries is a different value. The input to numericDeriv is not values but an expression. See the Examples section at the end of ?numericDeriv The expression given as the first arg ultimately needs to be evaluated at a value so it needs to know where to find that value. Note that it defaults to the caller's environment so we can leave that argument out if the variable is known to be there: X <- 3 numericDeriv(quote(X^2), "X") > > Can you please elaborate on that function? > > Thanks In Advance, > Oliver > > ______________________________________________ > 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. > ______________________________________________ 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.
