I would stay away from learning about 'while' and 'if' until you understand using '[' to select subsets. Subsetting is in chapter 2 of "An Introduction to R" and 'while' and 'if' are in chapter 9 for good reason.
Bill Dunlap Spotfire, TIBCO Software wdunlap tibco.com > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On > Behalf > Of Hal_V > Sent: Wednesday, September 18, 2013 3:23 PM > To: r-help@r-project.org > Subject: Re: [R] How to find values that correspond to a given value (i.e. > max) > > Thanks a lot to you both. > Both solutions work great, and thanks to will for explaining how this > works. I will have a look into while and if statements in R tomorrow... > > > 2013/9/18 William Dunlap [via R] <ml-node+s789695n4676466...@n4.nabble.com> > > > > If I have this: > > > > > > "names" <- c("John", "Jim", "Mary", "Susan") > > > "age" <- c(16, 25, 32, 56) > > > "income" <- c(2000, 3000, 2500, 1500) > > > "all"<- data.frame(names, age, income) > > > > First, things will be easier for you if you make that dataset as > > all <- data.frame( > > names = c("John", "Jim", "Mary", "Susan"), > > age = c(16, 25, 32, 56), > > income = c(2000, 3000, 2500, 1500)) > > so you don't have two things called "names", etc., one in the data.frame > > and one in the current environment. > > > > You can select subsets in R using the "[" operator. If it is given an > > integer > > argument it gives you the items indexed by that that integer vector; if > > given a logical argument it gives you the items corresponding to TRUE's > > in that logical vector. E.g., try > > x <- c(11,22,33,44) > > x[c(1,3)] # gives 11 and 33 > > x[c(TRUE, FALSE, TRUE, FALSE)] # also gives 11 and 33 > > > > Make a logical vector of showing which items in 'income' are equal to > > its maximum with > > atMaxIncome <- max(all$income) == all$income # gives, FALSE TRUE FALSE > > FALSE > > and do the selection with > > all[ atMaxIncome, ] > > > > > I tried some if-statements, but they didn't work because my programming > > > skills outside of SQL are basically non-existent. > > > > All of this is in Chapter 2 of "An Introduction to R" (about 4 pages into > > it), which comes with R. > > Read it and do the examples and your R programming skills will improve. > > > > Bill Dunlap > > Spotfire, TIBCO Software > > wdunlap tibco.com > > > > > -----Original Message----- > > > From: [hidden > email]<http://user/SendEmail.jtp?type=node&node=4676466&i=0>[mailto:[hidden > > email] <http://user/SendEmail.jtp?type=node&node=4676466&i=1>] On Behalf > > > Of Hal_V > > > Sent: Wednesday, September 18, 2013 12:43 PM > > > To: [hidden email]<http://user/SendEmail.jtp?type=node&node=4676466&i=2> > > > Subject: [R] How to find values that correspond to a given value (i.e. > > max) > > > > > > Hi everyone > > > I'm new to R, so this is probably a stupid question, but I looked around > > for > > > quite a while an couldn't find an answer. Basically I'm trying to print > > > values that correspond to a found maximum. > > > > > > If I have this: > > > > > > "names" <- c("John", "Jim", "Mary", "Susan") > > > "age" <- c(16, 25, 32, 56) > > > "income" <- c(2000, 3000, 2500, 1500) > > > "all"<- data.frame(names, age, income) > > > max(all$income) > > > > > > I would like to print the name and age that correspond to the found > > maximum. > > > I tried some if-statements, but they didn't work because my programming > > > skills outside of SQL are basically non-existent. > > > > > > I'd be glad for any pointers, thanks > > > > > > > > > > > > -- > > > View this message in context: > > http://r.789695.n4.nabble.com/How-to-find-values-that- > > > correspond-to-a-given-value-i-e-max-tp4676456.html > > > Sent from the R help mailing list archive at Nabble.com. > > > > > > ______________________________________________ > > > [hidden email] > > > <http://user/SendEmail.jtp?type=node&node=4676466&i=3>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. > > > > ______________________________________________ > > [hidden email] > > <http://user/SendEmail.jtp?type=node&node=4676466&i=4>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. > > > > > > ------------------------------ > > If you reply to this email, your message will be added to the discussion > > below: > > > > http://r.789695.n4.nabble.com/How-to-find-values-that-correspond-to-a-given-value- > i-e-max-tp4676456p4676466.html > > To unsubscribe from How to find values that correspond to a given value > > (i.e. max), click > here<http://r.789695.n4.nabble.com/template/NamlServlet.jtp?macro=unsubscribe_by_ > code&node=4676456&code=VGltLlVtYmFjaEBodWZ3LmRlfDQ2NzY0NTZ8MTg1MTc5NTE > yOQ==> > > . > > > NAML<http://r.789695.n4.nabble.com/template/NamlServlet.jtp?macro=macro_viewer > &id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicName > space-nabble.view.web.template.NabbleNamespace- > nabble.view.web.template.NodeNamespace&breadcrumbs=notify_subscribers%21nabbl > e%3Aemail.naml-instant_emails%21nabble%3Aemail.naml- > send_instant_email%21nabble%3Aemail.naml> > > > > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/How-to-find-values-that- > correspond-to-a-given-value-i-e-max-tp4676456p4676467.html > Sent from the R help mailing list archive at Nabble.com. > [[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.
