: Thanks. But when I apply your codes I get all NA instead of TRUE and FALSE
You need to show a self-contained example of your problem, one that others can copy and paste into their R sessions. E.g., data <- read.table(header=TRUE, stringsAsFactors=FALSE, text=" COL1 COL2 6/1/14 5/1/15 7/1/14 5/1/15") data$COL1<- as.Date(data$COL1, format="%d/%m/%y") data$COL2<- as.Date(data$COL2, format="%d/%m/%y") str(data) #'data.frame': 2 obs. of 2 variables: # $ COL1: Date, format: "2014-01-06" "2014-01-07" # $ COL2: Date, format: "2015-01-05" "2015-01-05" transform(data, `Col2>Col1` = COL2 > COL1, `Col2-Col1` = COL2 - COL1, check.names=FALSE) # COL1 COL2 Col2>Col1 Col2-Col1 #1 2014-01-06 2015-01-05 TRUE 364 days #2 2014-01-07 2015-01-05 TRUE 363 days Bill Dunlap TIBCO Software wdunlap tibco.com On Wed, Aug 23, 2017 at 9:09 AM, Patrick Casimir <patrc...@nova.edu> wrote: > > Thanks. But when I apply your codes I get all NA instead of TRUE and FALSE > > ________________________________ > From: PIKAL Petr <petr.pi...@precheza.cz> > Sent: Wednesday, August 23, 2017 11:20:00 AM > To: Patrick Casimir; r-help@r-project.org > Subject: RE: Comparing 2 dale columns > > Hi > > your code is wrong. > > I get > > test<-read.table("clipboard", header=T) > > str(test) > 'data.frame': 2 obs. of 2 variables: > $ COL1: Factor w/ 2 levels "6/1/14","7/1/14": 1 2 > $ COL2: Factor w/ 1 level "5/1/15": 1 1 > > test$COL2<- as.Date(as.character(test$COL2, format="%y/%m/%d")) > > test$COL1<- as.Date(as.character(test$COL1, format="%y/%m/%d")) > > ^^^^^^^^^^^^^^^^^^^^^^^ > incorrect parentheses position, wrong y,m,d > > Using correct syntax I get correct result. > > > test$COL2<- as.Date(test$COL2, format="%d/%m/%y") > > test$COL1<- as.Date(test$COL1, format="%d/%m/%y") > > > > test$COL2 > test$COL1 > [1] TRUE TRUE > > test > COL1 COL2 > 1 2014-01-06 2015-01-05 > 2 2014-01-07 2015-01-05 > > > > Cheers > Petr > > > -----Original Message----- > > From: R-help [mailto:r-help-boun...@r-project.org] On Behalf Of Patrick > > Casimir > > Sent: Wednesday, August 23, 2017 4:54 PM > > To: r-help@r-project.org > > Subject: [R] Comparing 2 dale columns > > > > Dear R fellows, > > > > > > I created a new column Date_flag to compare the dates of COL1 and COL2 > > using the code below. But it showed that 5/1/15 is greater than 6/1/2014 > and > > 5/1/2015 greater than > > 7/1/2014 despite the year is greater. How do I fix that? I did try to > format as > > %y/%m/%d > > > > but it does not fix that. > > > > > > data$Date_Flag <- ifelse(data$COL2 > data$COL1, 0,1) > > > > > > COL1 COL2 > > 6/1/14 5/1/15 > > 7/1/14 5/1/15 > > > > > > data$COL2<- as.Date(as.character(data$COL2, format="%y/%m/%d")) > > data$COL1<- as.Date(as.character(data$COL1, format="%y/%m/%d")) > > > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > > https://na01.safelinks.protection.outlook.com/?url= > https%3A%2F%2Fstat.ethz.ch%2Fmailman%2Flistinfo%2Fr-help& > data=02%7C01%7Cpatrcasi%40nova.edu%7Cbf182d25cae845ec841c08d4ea3a7139% > 7C2c2b2d312e3e4df1b571fb37c042ff1b%7C0%7C0%7C636390984126927971&sdata= > Tait17GF8fuEBwFnDZHCgnc7v88yXqAxpTX7W76O1cA%3D&reserved=0 > > PLEASE do read the posting guide https://na01.safelinks. > protection.outlook.com/?url=http%3A%2F%2Fwww.R-project. > org%2Fposting-guide.html&data=02%7C01%7Cpatrcasi%40nova.edu% > 7Cbf182d25cae845ec841c08d4ea3a7139%7C2c2b2d312e3e4df1b571fb37c042 > ff1b%7C0%7C0%7C636390984126927971&sdata=H3xZXXDLx4sN23A4HoUp1bElRZfWfP > T1HbOaRMSDCjI%3D&reserved=0 > > and provide commented, minimal, self-contained, reproducible code. > > ________________________________ > Tento e-mail a jakékoliv k němu připojené dokumenty jsou důvěrné a jsou > určeny pouze jeho adresátům. > Jestliľe jste obdrľel(a) tento e-mail omylem, informujte laskavě > neprodleně jeho odesílatele. Obsah tohoto emailu i s přílohami a jeho kopie > vymaľte ze svého systému. > Nejste-li zamýąleným adresátem tohoto emailu, nejste oprávněni tento email > jakkoliv uľívat, roząiřovat, kopírovat či zveřejňovat. > Odesílatel e-mailu neodpovídá za eventuální ąkodu způsobenou modifikacemi > či zpoľděním přenosu e-mailu. > > V případě, ľe je tento e-mail součástí obchodního jednání: > - vyhrazuje si odesílatel právo ukončit kdykoliv jednání o uzavření > smlouvy, a to z jakéhokoliv důvodu i bez uvedení důvodu. > - a obsahuje-li nabídku, je adresát oprávněn nabídku bezodkladně přijmout; > Odesílatel tohoto e-mailu (nabídky) vylučuje přijetí nabídky ze strany > příjemce s dodatkem či odchylkou. > - trvá odesílatel na tom, ľe přísluąná smlouva je uzavřena teprve > výslovným dosaľením shody na vąech jejích náleľitostech. > - odesílatel tohoto emailu informuje, ľe není oprávněn uzavírat za > společnost ľádné smlouvy s výjimkou případů, kdy k tomu byl písemně zmocněn > nebo písemně pověřen a takové pověření nebo plná moc byly adresátovi tohoto > emailu případně osobě, kterou adresát zastupuje, předloľeny nebo jejich > existence je adresátovi či osobě jím zastoupené známá. > > This e-mail and any documents attached to it may be confidential and are > intended only for its intended recipients. > If you received this e-mail by mistake, please immediately inform its > sender. Delete the contents of this e-mail with all attachments and its > copies from your system. > If you are not the intended recipient of this e-mail, you are not > authorized to use, disseminate, copy or disclose this e-mail in any manner. > The sender of this e-mail shall not be liable for any possible damage > caused by modifications of the e-mail or by delay with transfer of the > email. > > In case that this e-mail forms part of business dealings: > - the sender reserves the right to end negotiations about entering into a > contract in any time, for any reason, and without stating any reasoning. > - if the e-mail contains an offer, the recipient is entitled to > immediately accept such offer; The sender of this e-mail (offer) excludes > any acceptance of the offer on the part of the recipient containing any > amendment or variation. > - the sender insists on that the respective contract is concluded only > upon an express mutual agreement on all its aspects. > - the sender of this e-mail informs that he/she is not authorized to enter > into any contracts on behalf of the company except for cases in which > he/she is expressly authorized to do so in writing, and such authorization > or power of attorney is submitted to the recipient or the person > represented by the recipient, or the existence of such authorization is > known to the recipient of the person represented by the recipient. > > [[alternative HTML version deleted]] > > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > 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. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.