search for: wkdi

All, I am trying to include a day of week variable (1-7) in in a regression model. I would like to have the day of week treated as a categorical variable rather than a number the code looks like lm( dep ~ WKDY) I know this is a basic question, but help would be appreciated thanks spencer [[alternative HTML version deleted]]

hello, I am using arima to evaluate a time series regression model. I am using categorical variables such as day of week(Su-Sa), month(Jan-Dec), and holiday status (1/0) as my independent variables. There is evidence of multiplicative interaction between holiday status and weekday and I would like to add an interaction term to my arima model, but I am not sure about best way to go about doing it.

I am fittling a spline to a variable in a regression model, I am then using the predict.glm funtion to make some predictions. When I use bs to fit the spline I don't have any problems using the predict.glm function however when I use ns I get the following error: Error in model.frame(formula, rownames, variables, varnames, extras, extranames, : variable lengths differ (found for

Is there an R package that can model time series with multiple seasonal cycles, e.g., 7 wkdy x 24 hr , I have tried searching the Help, but have been unable to find anything. Any help would be appreciated. thank you, Spencer [[alternative HTML version deleted]]

I have been trying to find a command similiar to bs or ns to add a periodic/or cyclical splie term to a regression model in glm.nb I have been using ns to fit a spline to day of the year (1:365): glm.nb(CNT ~ WKDY + ns(DY,df=6) + HOLIDAY_FLAG + Trend) but I think a periodic spline might be more appropriate. Any suggestions would be appreciated. best, Spencer Jones, M.Stat. NLM Fellow Dept.