Hi, What about this,
eval(parse(text=expr)) (no print) HTH, baptiste 2009/9/19 Nick Matzke <mat...@berkeley.edu>: > Hi, > > I have a script which I source, which evaluates a changing expression call > hundreds of times. It works, but it prints to screen each time, which is > annoying. There must be simple way to suppress this, or to use a slightly > different set of commands, which will be obvious to those wiser than I... > > > Here is a simpler mockup which shows the issue: > > x = data.frame(rbind(c(1,2,3),c(1,2,3))) > xnames = c("a", "b", "c") > names(x) = xnames > > for(i in 1:length(x)) > { > # Create a varying string expression > expr = paste("y = x$", xnames[i], "[1]", sep="") > > # evaluate expression > eval(parse(text=print(expr))) > > # This command prints the expression to screen even when embedded in a > function in a sourced script. I would prefer it didn't! > } > > > PS: I have to go through this rigamarole: > > expr = "y1 = x$c[1]" > eval(parse(text=print(expr))) > > Because the following doesn't work, even though it seems like it should: > expr = "y = x$c[2]" > eval(expr) > > > > > -- > ==================================================== > Nicholas J. Matzke > Ph.D. Candidate, Graduate Student Researcher > Huelsenbeck Lab > Center for Theoretical Evolutionary Genomics > 4151 VLSB (Valley Life Sciences Building) > Department of Integrative Biology > University of California, Berkeley > > Lab websites: > http://ib.berkeley.edu/people/lab_detail.php?lab=54 > http://fisher.berkeley.edu/cteg/hlab.html > Dept. personal page: > http://ib.berkeley.edu/people/students/person_detail.php?person=370 > Lab personal page: http://fisher.berkeley.edu/cteg/members/matzke.html > Lab phone: 510-643-6299 > Dept. fax: 510-643-6264 > Cell phone: 510-301-0179 > Email: mat...@berkeley.edu > > Mailing address: > Department of Integrative Biology > 3060 VLSB #3140 > Berkeley, CA 94720-3140 > > ----------------------------------------------------- > "[W]hen people thought the earth was flat, they were wrong. When people > thought the earth was spherical, they were wrong. But if you think that > thinking the earth is spherical is just as wrong as thinking the earth is > flat, then your view is wronger than both of them put together." > > Isaac Asimov (1989). "The Relativity of Wrong." The Skeptical Inquirer, > 14(1), 35-44. Fall 1989. > http://chem.tufts.edu/AnswersInScience/RelativityofWrong.htm > > ______________________________________________ > 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.