[R] Use a text variable's value to specify another varaible?
Greetings guRus -- If a variable, e.g., 'varname', is a character string, e.g. varname - datavector, and I want to apply a function, such as table(), to datavector, what syntax or method will do so using only the variable varname? This seems similar to indirect addressing, but I have not seen a method for it in the R manuals. Is there a general name for such indirect reference that one might search for? (This came up while writing a function that takes the value of 'varname' from the keyboard and then applies functions to it.) With thanks for any solution, Ben Fairbank [[alternative HTML version deleted]] __ R-help@stat.math.ethz.ch 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] Use a text variable's value to specify another varaible?
On Fri, 2007-01-26 at 09:48 -0600, Ben Fairbank wrote: Greetings guRus -- If a variable, e.g., 'varname', is a character string, e.g. varname - datavector, and I want to apply a function, such as table(), to datavector, what syntax or method will do so using only the variable varname? This seems similar to indirect addressing, but I have not seen a method for it in the R manuals. Is there a general name for such indirect reference that one might search for? (This came up while writing a function that takes the value of 'varname' from the keyboard and then applies functions to it.) With thanks for any solution, Ben Fairbank See ?get and ?assign datavector - 1:10 varname - datavector get(varname) [1] 1 2 3 4 5 6 7 8 9 10 log10(get(varname)) [1] 0.000 0.3010300 0.4771213 0.6020600 0.6989700 0.7781513 [7] 0.8450980 0.9030900 0.9542425 1.000 and/or assign(varname, letters) datavector [1] a b c d e f g h i j k l m n o p q [18] r s t u v w x y z get(varname) [1] a b c d e f g h i j k l m n o p q [18] r s t u v w x y z HTH, Marc Schwartz __ R-help@stat.math.ethz.ch 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] Use a text variable's value to specify another varaible?
Can I ask why you aren't just passing in the object to your function, but instead a text name for that object? Ben Fairbank wrote: Greetings guRus -- If a variable, e.g., 'varname', is a character string, e.g. varname - datavector, and I want to apply a function, such as table(), to datavector, what syntax or method will do so using only the variable varname? This seems similar to indirect addressing, but I have not seen a method for it in the R manuals. Is there a general name for such indirect reference that one might search for? (This came up while writing a function that takes the value of 'varname' from the keyboard and then applies functions to it.) With thanks for any solution, Ben Fairbank [[alternative HTML version deleted]] __ R-help@stat.math.ethz.ch 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@stat.math.ethz.ch 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.
