Hi, I am new to R. Can anyone tell me how to evaluate an expression stored in a string? such as:> expr <- "3*5"I want to get the result 15. Thanks in advance.
Hi, Ning, Try: eval(parse(text = expr)) HTH, --sundar On Sat, May 2, 2009 at 5:39 AM, Ning Ma <pningma at gmail.com> wrote:> Hi, > > I am new to R. Can anyone tell me how to evaluate an expression stored > in a string? > such as: >> expr <- "3*5" > I want to get the result 15. > > Thanks in advance. > > ______________________________________________ > 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. >
> eval(parse(text=expr))[1] 15 2009/5/2 Ning Ma <pningma at gmail.com>:> Hi, > > I am new to R. Can anyone tell me how to evaluate an expression stored > in a string? > such as: >> expr <- "3*5" > I want to get the result 15. > > Thanks in advance. > > ______________________________________________ > 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. >-- HUANG Ronggui, Wincent PhD Candidate Dept of Public and Social Administration City University of Hong Kong Home page: http://asrr.r-forge.r-project.org/rghuang.html
Thank you and Sunder! On Sat, May 2, 2009 at 8:49 PM, ronggui <ronggui.huang at gmail.com> wrote:>> eval(parse(text=expr)) > [1] 15 > > > 2009/5/2 Ning Ma <pningma at gmail.com>: >> Hi, >> >> I am new to R. Can anyone tell me how to evaluate an expression stored >> in a string? >> such as: >>> expr <- "3*5" >> I want to get the result 15. >> >> Thanks in advance. >> >> ______________________________________________ >> 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. >> > > > > -- > HUANG Ronggui, Wincent > PhD Candidate > Dept of Public and Social Administration > City University of Hong Kong > Home page: http://asrr.r-forge.r-project.org/rghuang.html >