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/
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