Hey,
I'm trying to find how to perform operations with a variable treated as a
symbol.
For, an extremely simple, example I want to integrate a*x with respect to x
and I want to find the indefinite integral of this, (a*x^2/2), or the
definite integral with some interval for x.
Another example of such a use would be to create a function
y<-function(x) {a*x}
and by typig y(2) I would get the result 2*a
Is there a way to treat variables as merely "symbols"?
Any help much appreciated
-M
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Hi Zemajik, Try this:> y <- function(a) paste(a, '*x', sep="") > y(2)[1] "2*x" Also, take a look at the Ryacas package. HTH, Jorge On Thu, Oct 1, 2009 at 9:46 AM, ZeMajik <> wrote:> Hey, > I'm trying to find how to perform operations with a variable treated as a > symbol. > For, an extremely simple, example I want to integrate a*x with respect to x > and I want to find the indefinite integral of this, (a*x^2/2), or the > definite integral with some interval for x. > > Another example of such a use would be to create a function > y<-function(x) {a*x} > and by typig y(2) I would get the result 2*a > > Is there a way to treat variables as merely "symbols"? > Any help much appreciated > > -M > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. >[[alternative HTML version deleted]]
Try this: y <- function(a) substitute(a * x, list(a = a)) On Thu, Oct 1, 2009 at 10:46 AM, ZeMajik <zemajik at gmail.com> wrote:> Hey, > I'm trying to find how to perform operations with a variable treated as a > symbol. > For, an extremely simple, example I want to integrate a*x with respect to x > and I want to find the indefinite integral of this, (a*x^2/2), or the > definite integral with some interval for x. > > Another example of such a use would be to create a function > y<-function(x) {a*x} > and by typig y(2) I would get the result 2*a > > Is there a way to treat variables as merely "symbols"? > Any help much appreciated > > -M > > ? ? ? ?[[alternative HTML version deleted]] > > ______________________________________________ > R-help at 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. >-- Henrique Dallazuanna Curitiba-Paran?-Brasil 25? 25' 40" S 49? 16' 22" O