[R] Treating variables as symbols
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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Re: [R] Treating variables as symbols
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]]
__
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.
Re: [R] Treating variables as symbols
Try this:
y - function(a)
substitute(a * x, list(a = a))
On Thu, Oct 1, 2009 at 10:46 AM, ZeMajik zema...@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@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-Paraná-Brasil
25° 25' 40 S 49° 16' 22 O
__
R-help@r-project.org mailing list
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
Re: [R] Treating variables as symbols
Thanks guys, Ryacas is pretty much what I'm looking for!However, I can't
seem to get it to work properly.
For example:
yacas(Integrate(x) x)
Error in parse(text = text, srcfile = NULL) :
unexpected numeric constant in / (^ (x ,2 2
Same thing with expressions such as yacas(x*x)
However
yacas(2*2)
expression(4)
So it seems there is a successful connection between yacas and R.
I didn't find any info on the problem by googling it unfortunately! Any
ideas what it might be?
Thanks again,
M
On Thu, Oct 1, 2009 at 3:50 PM, Jorge Ivan Velez
jorgeivanve...@gmail.comwrote:
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]]
__
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.
Re: [R] Treating variables as symbols
Read the troubleshooting section on the home page: http://ryacas.googlecode.com
Note, in particular, that it currently only works with an older
version of the XML package.
library(Ryacas)
packageDescription(XML)$Version
[1] 1.96-0
x - Sym(x)
Integrate(x*x, x)
[1] Starting Yacas!
expression(x^3/3)
On Thu, Oct 1, 2009 at 11:08 AM, ZeMajik zema...@gmail.com wrote:
Thanks guys, Ryacas is pretty much what I'm looking for!However, I can't
seem to get it to work properly.
For example:
yacas(Integrate(x) x)
Error in parse(text = text, srcfile = NULL) :
unexpected numeric constant in / (^ (x ,2 2
Same thing with expressions such as yacas(x*x)
However
yacas(2*2)
expression(4)
So it seems there is a successful connection between yacas and R.
I didn't find any info on the problem by googling it unfortunately! Any
ideas what it might be?
Thanks again,
M
On Thu, Oct 1, 2009 at 3:50 PM, Jorge Ivan Velez
jorgeivanve...@gmail.comwrote:
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]]
__
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.
