IHi All, l, I am reading a csv file and one of the columns is named as "mydate" with this form, 2019-09-16. I am reading this file as dat=read.csv("myfile.csv") the structure of the data looks like as follow str(dat) mydate : chr "09/16/2019" "02/21/2021" "02/22/2021" "10/11/2017" ... Please note the format has changed from YYYY-mm-dd to mm/dd/YYYY When I tried to change this as a Date using as.Date(as.Date(mydate, format="%m/%d/%Y" ) I am getting this error message Error in charToDate(x) : characte string is not in a standard unambiguous format My question is, 1. how can I read the file as it is (i.e., without changing the date format) ? 2. why does R change the date format? Thank you,
You are claiming behavior that is not something R does, but is something Excel does constantly. Compare what your data file looks like using a text editor with what R has imported. Absolutely do not use a spreadsheet program to do this. On November 4, 2021 2:43:25 PM PDT, Val <valkremk at gmail.com> wrote:>IHi All, l, > >I am reading a csv file and one of the columns is named as "mydate" > with this form, 2019-09-16. > >I am reading this file as > >dat=read.csv("myfile.csv") > the structure of the data looks like as follow > >str(dat) >mydate : chr "09/16/2019" "02/21/2021" "02/22/2021" "10/11/2017" ... > >Please note the format has changed from YYYY-mm-dd to mm/dd/YYYY >When I tried to change this as a Date using > >as.Date(as.Date(mydate, format="%m/%d/%Y" ) >I am getting this error message > Error in charToDate(x) : > characte string is not in a standard unambiguous format > >My question is, >1. how can I read the file as it is (i.e., without changing the date format) ? >2. why does R change the date format? > >Thank you, > >______________________________________________ >R-help at 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.-- Sent from my phone. Please excuse my brevity.
Hi Val, Try this: dat=read.csv("myfile.csv",stringsAsFactors=FALSE) However, the apparently silent conversion of format is a mystery to me. The only time I have struck something like this was when exporting dates from Excel some years ago, and there was a silent conversion to mm/dd/yyyy format if the dates were in dd/mm/yyyy format. Could you post some sample data? Jim On Fri, Nov 5, 2021 at 8:44 AM Val <valkremk at gmail.com> wrote:> > IHi All, l, > > I am reading a csv file and one of the columns is named as "mydate" > with this form, 2019-09-16. > > I am reading this file as > > dat=read.csv("myfile.csv") > the structure of the data looks like as follow > > str(dat) > mydate : chr "09/16/2019" "02/21/2021" "02/22/2021" "10/11/2017" ... > > Please note the format has changed from YYYY-mm-dd to mm/dd/YYYY > When I tried to change this as a Date using > > as.Date(as.Date(mydate, format="%m/%d/%Y" ) > I am getting this error message > Error in charToDate(x) : > characte string is not in a standard unambiguous format > > My question is, > 1. how can I read the file as it is (i.e., without changing the date format) ? > 2. why does R change the date format? > > Thank you, > > ______________________________________________ > R-help at 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.
Hi Not sure why the date format was changed but if I am correct R do not read dates as dates but as character vector. You need to transfer such columns to dates by asDate. The error is probably from your use two asDate commands. Cheers Petr -----Original Message----- From: R-help <r-help-bounces at r-project.org> On Behalf Of Val Sent: Thursday, November 4, 2021 10:43 PM To: r-help at R-project.org (r-help at r-project.org) <r-help at r-project.org> Subject: [R] Date IHi All, l, I am reading a csv file and one of the columns is named as "mydate" with this form, 2019-09-16. I am reading this file as dat=read.csv("myfile.csv") the structure of the data looks like as follow str(dat) mydate : chr "09/16/2019" "02/21/2021" "02/22/2021" "10/11/2017" ... Please note the format has changed from YYYY-mm-dd to mm/dd/YYYY When I tried to change this as a Date using as.Date(as.Date(mydate, format="%m/%d/%Y" ) I am getting this error message Error in charToDate(x) : characte string is not in a standard unambiguous format My question is, 1. how can I read the file as it is (i.e., without changing the date format) ? 2. why does R change the date format? Thank you, ______________________________________________ R-help at 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. Osobn? ?daje: Informace o zpracov?n? a ochran? osobn?ch ?daj? obchodn?ch partner? PRECHEZA a.s. jsou zve?ejn?ny na: https://www.precheza.cz/zasady-ochrany-osobnich-udaju/ | Information about processing and protection of business partner?s personal data are available on website: https://www.precheza.cz/en/personal-data-protection-principles/ D?v?rnost: Tento e-mail a jak?koliv k n?mu p?ipojen? dokumenty jsou d?v?rn? a podl?haj? tomuto pr?vn? z?vazn?mu prohl??en? o vylou?en? odpov?dnosti: https://www.precheza.cz/01-dovetek/ | This email and any documents attached to it may be confidential and are subject to the legally binding disclaimer: https://www.precheza.cz/en/01-disclaimer/