Hi, I'm new to R. I've two sort of time series, one sampled every second and other every 30 minutes stored in two data.frames zy1 and zy2. I've joined the two series using date<-merge(zy1,zy2, all.x=T,all.y=T) when I want to make a plot, using the code below, it doesn't work. It gives me the following error "produced NA error" plot( a~ time,data=z, type="l", ylim=range(30,80)) lines( b~ time,data=z, type="l") Can you help me? Thanks Morgi -- View this message in context: http://old.nabble.com/plotting-time-series-tp26308476p26308476.html Sent from the R help mailing list archive at Nabble.com.