Hi everyone, I have been trying to compute numbers of days between two dates as follows:> x <- c("1jan1960", "2jan1960", "31mar1960", "30jul1960") > z <- format(x, "%d%b%Y") > ex <- c("1jan1961", "15jan1960", "21mar1975", "10jul1981") > ez <- format(ex, "%d%b%Y") > ez-zError in ez - z : non-numeric argument to binary operator As you may see, I am getting an error. Can anyone tell me how I can convert z and ez to numeric vectors, so that I can compute days between the corresponding dates in these vectors? thank you soyoko ______________________________________ Ms. Soyoko Umeno Graduate Research Assitant for the Illinois-Missouri Biotechnology Alliance (IMBA) at http://www.imba.missouri.edu/ Ph.D. Student at the Department of Agricultural and Consumer Economics at the University of Illinois at Urbana-Champaign Office Phone: 217-333-3417 or 217-333-0364 Fax: 217-244-4817 Mailing Address: 1301 W. Gregory Dr. MC710, Urbana, IL 61801
?strptime ?as.POSIXct ?difftime On Wed, 5 Nov 2003, umeno wrote:> Hi everyone, > > I have been trying to compute numbers of days between two dates as follows: > > > x <- c("1jan1960", "2jan1960", "31mar1960", "30jul1960") > > z <- format(x, "%d%b%Y") > > ex <- c("1jan1961", "15jan1960", "21mar1975", "10jul1981") > > ez <- format(ex, "%d%b%Y") > > ez-z > Error in ez - z : non-numeric argument to binary operator > > As you may see, I am getting an error. Can anyone tell me how I can convert z > and ez to numeric vectors, so that I can compute days between the > corresponding dates in these vectors? > > thank you > soyoko > > ______________________________________ > Ms. Soyoko Umeno > Graduate Research Assitant for the Illinois-Missouri Biotechnology Alliance (IMBA) at http://www.imba.missouri.edu/ > Ph.D. Student at the Department of Agricultural and Consumer Economics > at the University of Illinois at Urbana-Champaign > Office Phone: 217-333-3417 or 217-333-0364 > Fax: 217-244-4817 > Mailing Address: 1301 W. Gregory Dr. MC710, Urbana, IL 61801 > > ______________________________________________ > R-help at stat.math.ethz.ch mailing list > https://www.stat.math.ethz.ch/mailman/listinfo/r-help > >-- Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595
ndays <- strptime(ex,format="%d%b%Y") - strptime(x,format="%d%b%Y") If you need it in a calculation then as.numeric(ndays) might be useful. --- Date: Wed, 5 Nov 2003 23:33:33 -0600 From: umeno <umeno at students.uiuc.edu> To: R-Help Subject: [R] Number of Days Hi everyone, I have been trying to compute numbers of days between two dates as follows:> x <- c("1jan1960", "2jan1960", "31mar1960", "30jul1960") > z <- format(x, "%d%b%Y") > ex <- c("1jan1961", "15jan1960", "21mar1975", "10jul1981") > ez <- format(ex, "%d%b%Y") > ez-zError in ez - z : non-numeric argument to binary operator As you may see, I am getting an error. Can anyone tell me how I can convert z and ez to numeric vectors, so that I can compute days between the corresponding dates in these vectors? thank you soyoko ______________________________________ Ms. Soyoko Umeno Graduate Research Assitant for the Illinois-Missouri Biotechnology Alliance (IMBA) at http://www.imba.missouri.edu/ Ph.D. Student at the Department of Agricultural and Consumer Economics at the University of Illinois at Urbana-Champaign Office Phone: 217-333-3417 or 217-333-0364 Fax: 217-244-4817 Mailing Address: 1301 W. Gregory Dr. MC710, Urbana, IL 61801 _______________________________________________ No banners. No pop-ups. No kidding. Introducing My Way - http://www.myway.com