[R] Converting daily data series to monthly series

[Rubén Roa]

> -----Mensaje original-----
> De: r-help-bounces at r-project.org 
> [mailto:r-help-bounces at r-project.org] En nombre de zowiti at ncst.go.ke
> Enviado el: miércoles, 21 de abril de 2010 5:16
> Para: r-help at r-project.org
> Asunto: [R] Converting daily data series to monthly series
> 
> Hi Users,
> I have daily series of data from 1962 - 2000, with  the data 
> for February 29th in leap years  excluded, leaving 365 daily 
> values for each year. I wish to convert the daily series to 
> monthly series. How can I do this using the zoo package or 
> any other package?
> 
> Thanks 
> 
> ZABLONE OWITI
>  GRADUATE STUDENT
> Nanjing University of Information, Science and Technology 
> College of International Education

Let df be your dataframe,

#In case you have to format your data as date before setting the montth
df$date   <- as.Date(df$date, "%d/%m/%Y")
#Getting year, month and week from your correctly formatted date
df$Year   <- as.numeric(format(df$date, "%Y"))    #Year
df$Month  <- as.numeric(format(df$date, "%m"))    #Month
df$Week   <- as.numeric(format(df$date, "%W")) +1 #Week

____________________________________________________________________________________ 

Dr. Rubén Roa-Ureta
AZTI - Tecnalia / Marine Research Unit
Txatxarramendi Ugartea z/g
48395 Sukarrieta (Bizkaia)
SPAIN