Hi everyone, Im quite new to R an I have the following Question: I would like to define Variables which I can add and multiply etc. and that R can simplyfy the terms. The variables should stand for integers. For example I would like to have an entry in an array with variable z and if I add b+z the field should now contain 2z+b. Or if the field contains 1 and I add z the field should contain 1+z. How can I solve this problem? I tried to set z=integer and then for example matrix[1,1]=i But this does only work if I assign a value for z first. I am very grateful for any help. Thank you very much! David -- View this message in context: http://www.nabble.com/Question-on-Variables-tp22388117p22388117.html Sent from the R help mailing list archive at Nabble.com.
myArray[, 'z'] <- myArray[, 'z'] + b Is this what you want? On Sat, Mar 7, 2009 at 9:52 AM, David1234 <danielthurm at web.de> wrote:> > Hi everyone, > > Im quite new to R an I have the following Question: > > > I would like to define Variables which I can add and multiply etc. and that > R can simplyfy the terms. > > The variables should stand for integers. > For example I would like to have an entry in an array with variable ? z > and if I ?add ? ?b+z ? ?the field should now contain 2z+b. ?Or if the field > contains ? 1 ? ?and I add ? ?z ? ?the field should contain 1+z. > > How can I solve this problem? > > I tried to set z=integer and then for example matrix[1,1]=i > But this does only work if I assign a value for z first. > > I am very grateful for any help. > > > Thank you very much! > > David > -- > View this message in context: http://www.nabble.com/Question-on-Variables-tp22388117p22388117.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. >-- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem that you are trying to solve?
I fear that you are looking for a symbolic algebra system, and R is not that sort of platform. If I am correct and you still want to access a symbolic algebra system from R, then you should look at YACAS and the interface to it, Ryacas. -- David Winsemius On Mar 7, 2009, at 9:52 AM, David1234 wrote:> > Hi everyone, > > Im quite new to R an I have the following Question: > > > I would like to define Variables which I can add and multiply etc. > and that > R can simplyfy the terms. > > The variables should stand for integers. > For example I would like to have an entry in an array with > variable z > and if I add b+z the field should now contain 2z+b. Or if > the field > contains 1 and I add z the field should contain 1+z. > > How can I solve this problem? > > I tried to set z=integer and then for example matrix[1,1]=i > But this does only work if I assign a value for z first. > > I am very grateful for any help. > > > Thank you very much! > > David > -- > View this message in context: http://www.nabble.com/Question-on-Variabeles-tp22388117p22388117.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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.David Winsemius, MD Heritage Laboratories West Hartford, CT
David1234 wrote:> Hi everyone, > > Im quite new to R an I have the following Question: > > > I would like to define Variables which I can add and multiply etc. and that > R can simplyfy the terms. > > The variables should stand for integers. > For example I would like to have an entry in an array with variable z > and if I add b+z the field should now contain 2z+b. Or if the field > contains 1 and I add z the field should contain 1+z. > > How can I solve this problem? > > I tried to set z=integer and then for example matrix[1,1]=i > But this does only work if I assign a value for z first. > > I am very grateful for any help. > > > Thank you very much! > > DavidR is not an algebra system but a system for numerical computations. You can write a function that represents (i.e. generates and returns) your matrix and uses its arguments to fill different elements of that matrix. Best wishes, Uwe