Hello, I am attempting to use R as part of a time-series analysis investigating the influence of meteorological factors on health outcomes. The test csv dta file that i am working with contains a complete daily set of the variables ?DATE?, ?ADMINS?, ?NOX?, ?TEMP? across a 5 year period (1827 days). Within attempting to fit a GLM, I believe that I am having difficulty with the ns function, although problems could also be arising through date functions in R. Attached is my code and following errors, as a new starter within the world of R any help would be much appreciated. ## [1] Original Analysis: FAILS ## packages loaded for use within my wider data analysis library(splines) library(xtable) library(tsModel) library(lattice) library(mda) library(gam) ## splines: For date there are 4 seasons across 5 years ## splines: For temp cold and warm seasons are 6 months long fit <- glm(J00_99 ~ NOX_LIN + ns(DATE_B, 4 * 5) + ns(TEMP_LIN, 6), data = data, family = poisson) ### Error in (1 - h) * qs[i] : non-numeric argument to binary operator pr <- predict(fit, type = "terms") ### Error in predict(fit, type = "terms") : object 'fit' not found ## [2] Attempt 2: FAILS ##### So I have also been informed that when working with date i should use the chron ##### package to convert the dates within my data file to a usable format. This could be causing such problems library(chron) dates<-as.POSIXct(strptime(data[, "DATE"], format = "%d/%m/%Y", "GMT")) fit <- glm(ADMINS ~ NOX + ns(date, 4 * 5) + ns(TEMP, 6), data = data, family = poisson) ## Error in as.vector(x, mode) : cannot coerce type 'closure' to vector of type 'any' -- View this message in context: http://r.789695.n4.nabble.com/Fitting-a-GLM-Problems-with-ns-date-functions-tp3850379p3850379.html Sent from the R help mailing list archive at Nabble.com.