loess for time series with missing data

Question

I have a problem using loess and loess.smooth with a timeline next to missing data.

Both teams do not work with these toys.

 x <- as.Date(c(1, 2, 4, 5, 6), origin="2010-1-1") y <- c(4, 8, 8, 28, 11) plot(x, y, ylim=c(1,30)) lines(loess(y ~ x), col="red") lines(loess.smooth(y=y, x=x), col="blue") 

Answer 1

I ended up using the following code:

 # Data x.1 <- as.Date(c(1, 2, 4, 5, 6), origin="2010-1-1") x.2 <- c(1, 2, 4, 5, 6) y <- c(4, 8, 8, 28, 11) # x.2 - x is numeric variable plot(x.2, y, ylim=c(1,30)) lines(loess(y ~ x.2, span=1.01), col="black", lwd=2, lty=2) # neccessary to change span default to avoid warnings (span = 0.75) lines(loess.smooth(x.2, y, span=1.01), col = "orange", , lwd=2) # neccessary to change span default to avoid warnings (span = 2/3) lines(smooth.spline(x.2,y), col="blue", lwd=2) # x.1 - x is date variable plot(x.1, y, ylim=c(1,30)) # loess() cannot deal with date variables, thus convert it to lines(loess(y~as.numeric(x.1), span=1.01), col="red", lwd=2) # neccessary to change span default to avoid warnings (span = 0.75) lines(loess.smooth(x.1, y, span=1.01), col = "orange", lwd=2) # neccessary to change span default to avoid warnings (span = 2/3) lines(smooth.spline(x.1,y), col="blue", lwd=2) 

The problems were: (1) loess cannot deal with date variables. (2) The span parameter should have been adjusted (> 1).