


Hi All, 

 

I have a data set of daily measurements of river flow. 
I would like to create a “ts” object from this data.   

 

Here’s a sample data set:

date <- as.Date(c(1:300), format="%Y")

year=as.numeric(format(date, format = "%Y"))

month=as.numeric(format(date, format = "%m"))

julianday=as.numeric(format(date, format = "%j"))

week=floor(julianday/7)

flow <- sin(2*pi/53*c(1:300))

data <- cbind.data.frame(date,year,month,julianday,week,
flow)

 

I know how to do this with exact dates using the irts
package:

install.packages("tseries")

library(tseries)

data=cbind.data.frame(data,posixlt.time=as.POSIXlt(data$date,
"PDT")) ##To create dates based on POSIXlt

data.irts=irts(data$posixlt.time, data$flow)

 

But I would like the time series object to be in the “ts”
format.  I tried using this code:

 

data.ts=ts(data$flow, start=c(data$year[1],
data$julianday[1]), frequency=365)

 

Which does work, but I worry about the influence of leap
years, since my data set is quite large.  What is the way to properly code
a ts object with daily measurements?  Thank you!

 

-Pam

 

Pam Allen

Vancouver, BC

 		 	   		  
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