Maybe, you can add a parameter with a list of the column names and inside the function an if statement, if the list lenght is 1 use the function with 1 column else the 3 columns. I am sure you can find better solutions.
Daniel Merino 2014-11-04 9:30 GMT-03:00 Frederic Ntirenganya <ntfr...@gmail.com>: > Hi Daniel, > > How can I add an if conditiopn or for loop to implement this in my > function? > > ex: option1 : single date > option2: date in 3 columns (year,moth,day) > > yday(Sys.Date()) > yday(as.Date(paste(y,m,d,sep="-"))) > > Regards, > Frederic. > > > Frederic Ntirenganya > Maseno University, > African Maths Initiative, > Kenya. > Mobile:(+254)718492836 > Email: fr...@aims.ac.za > https://sites.google.com/a/aims.ac.za/fredo/ > > On Tue, Nov 4, 2014 at 3:20 PM, daniel <daniel...@gmail.com> wrote: > >> Frederic, >> >> Check the lubridate library. >> >> install.packages("lubridate") >> library(lubridate) >> yday(Sys.Date()) >> d <- 4 >> m <- 11 >> y <- 2014 >> yday(as.Date(paste(y,m,d,sep="-"))) >> >> Daniel Merino >> >> 2014-11-04 7:01 GMT-03:00 Frederic Ntirenganya <ntfr...@gmail.com>: >> >>> Dear All, >>> >>> I would like to make a function that create Day of the year column in a >>> dataset. >>> State of the problem: write a function that create a day column either >>> from >>> a single date column (string/or factors) or from date in 3 columns (year, >>> month, day). >>> >>> I made the following function for a single date. I would like to add a >>> condition for date in 3 columns (year, month, day). My data is daily >>> climate data. >>> #write a function that create a day column either from a single date >>> column >>> (string/or factors) >>> #or from date in 3 columns (year, month, day). >>> >>> DOY=function(data){ >>> >>> #================================================================= >>> #This function create day of teh year from a single date >>> column(ex:2009-08-02) or/and >>> #from the date in 3 columns (Year, month, Day). >>> #================================================================ >>> data$Rain=as.numeric(as.character(data$Rain)) >>> dt=yday(data$Date) # single date of the data >>> datelp= dt>59 & !leap_year(data$Date)# tell us that the date occurs >>> during a leap year >>> dt[datelp]=dt[datelp]+1 # add one for non leap_year >>> cbind(data, dt) # combining columns of data >>> conames(data)="DOY" # name of new column. ??I have a problem on how I >>> can >>> precise the column in gerenal. >>> } >>> >>> ex: year month day Date Rain Tmin Tmax >>> 1971 1 1 1971-01-01 0 8.2 15 >>> 1971 1 2 1971-01-02 0 4.2 11 >>> . . . . . . . >>> . . . . . . . >>> . . . . . . . >>> >>> Any ideal on how I can make this function is welcome. thanks! >>> Frederic Ntirenganya >>> Maseno University, >>> African Maths Initiative, >>> Kenya. >>> Mobile:(+254)718492836 >>> Email: fr...@aims.ac.za >>> https://sites.google.com/a/aims.ac.za/fredo/ >>> >>> [[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. >>> >> >> >> >> -- >> Daniel >> > > -- Daniel [[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.
