Welcome to the R community! I see you already learned some of the data selection methods using []. You can use the same principles to subset data i.e.
dat=read.table("clipboard") #reading the data you posted, after copied to my clipboard dat start therms gas KWHs elect temp days 1 10-Jun-98 9 16.84 613 63.80 75 40 2 20-Jul-98 6 15.29 721 74.21 76 29 3 18-Aug-98 7 15.73 597 62.22 76 29 4 16-Sep-98 42 35.81 460 43.98 70 33 5 19-Oct-98 105 77.28 314 31.45 57 29 6 17-Nov-98 106 77.01 342 33.86 48 30 subDat=dat[dat$temp<65,] #Subsetting only days with temp<65. Notice the use of commas and $ here subDat start therms gas KWHs elect temp days 5 19-Oct-98 105 77.28 314 31.45 57 29 6 17-Nov-98 106 77.01 342 33.86 48 30 You can also use the higher level function subset i.e. subDat=subset(dat, temp <65) subDat start therms gas KWHs elect temp days 5 19-Oct-98 105 77.28 314 31.45 57 29 6 17-Nov-98 106 77.01 342 33.86 48 30 I would encourage you to invest some time reading the pdf manual available in the main console under Help->Manuals (in pdf) -> An Introduction to R I hope this helps Francisco Dr. Francisco J. Zagmutt College of Veterinary Medicine and Biomedical Sciences Colorado State University >From: "Zembower, Kevin" <[EMAIL PROTECTED]> >To: <r-help@stat.math.ethz.ch> >Subject: [R] Newbie: Selecting data >Date: Thu, 19 Oct 2006 16:12:54 -0400 > >I've been working with R for all of about 8 hours, so anyone with more >experience than this should be able to help me. General comments about >my methods of work are also welcomed. > >I have a table that I've imported thusly: > > w <- read.table("woodford.data", header=T) > > w > start therms gas KWHs elect temp days >1 10-Jun-98 9 16.84 613 63.80 75 40 >2 20-Jul-98 6 15.29 721 74.21 76 29 >3 18-Aug-98 7 15.73 597 62.22 76 29 >4 16-Sep-98 42 35.81 460 43.98 70 33 >5 19-Oct-98 105 77.28 314 31.45 57 29 >6 17-Nov-98 106 77.01 342 33.86 48 30 ><snip> > >[This is real data on my house.] 'days' is number of days in bill, >'temp' is average temperature in Fahrenheit. I'd like to see if there is >a relationship between the gas burned (therms) and the number of heating >degree days. > >I compute therms per day and heating degree days like this: > > thermsperday <- w[,2]/w[,7] > > hdd <- (w[,6] -65)*w[,7] > >However, I only want the data for the months in which the average >temperature is less than 65 (otherwise, it's a cooling degree day). I >tried ifelse, but couldn't get it to work. What simple technique am I >overlooking? > >Thanks so much for your help and suggestions, especially for your >patience with a newbie. > >-Kevin > >Kevin Zembower >Internet Services Group manager >Center for Communication Programs >Bloomberg School of Public Health >Johns Hopkins University >111 Market Place, Suite 310 >Baltimore, Maryland 21202 >410-659-6139 > >______________________________________________ >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. _________________________________________________________________ Get today's hot entertainment gossip ______________________________________________ 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.