Hi, I am trying to plot the following time series: Low sampling rate Low sampling rate Sample High sampling rate High sampling rate Sample 09:50:00 4.474203 09:50:37 4.465 10:00:00 4.493805 09:50:38 4.452 10:10:00 4.503606 09:50:39 4.451 10:20:00 4.513407 09:50:40 4.465 10:30:00 4.503606 09:50:41 4.456 10:40:00 4.464402 09:50:42 4.469 10:50:00 4.425198 09:50:43 4.454 This is my code: Sampling_rates<-data.frame(LOAD_DATA[zero:nrow(LOAD_DATA),zero:ncol(LOAD_DATA)]) Sampling_rates_Labels<-names(LOAD_DATA[zero:nrow(LOAD_DATA),zero:ncol(LOAD_DATA)]) ### LOW_SAMPLING<-matrix(MV,nrow(LOAD_DATA),two) HIGH_SAMPLING<-matrix(MV,nrow(LOAD_DATA),two) colnames(LOW_SAMPLING)<-c("LOW_SAMPLING_RATE","LOW_SAMPLING") colnames(HIGH_SAMPLING)<-c("HIGH_SAMPLING_RATE","HIGH_SAMPLING") ### Find all LOW_SAMPLING values for (i in one:nrow(LOAD_DATA)) if (Sampling_rates_Labels[one]=="Low.sampling.rate") LOW_SAMPLING[i,one]<-(LOAD_DATA[i,one]) for (j in one:nrow(LOAD_DATA)) if (Sampling_rates_Labels[two]=="Low.sampling.rate.Sample") LOW_SAMPLING[j,two]<-(LOAD_DATA[j,two]) for (i in one:nrow(LOAD_DATA)) if (LOW_SAMPLING[i,one]=="") LOW_SAMPLING_ONLY<-LOW_SAMPLING[!apply(LOW_SAMPLING=="",MARGIN=one,any),] ### Find all HIGH_SAMPLING values for (i in one:nrow(LOAD_DATA)) if (Sampling_rates_Labels[three]=="High.sampling.rate") HIGH_SAMPLING[i,one]<-(LOAD_DATA[i,three]) for (j in one:nrow(LOAD_DATA)) if (Sampling_rates_Labels[four]=="High.sampling.rate.Sample") HIGH_SAMPLING[j,two]<-(LOAD_DATA[j,four]) for (i in one:nrow(LOAD_DATA)) if (LOAD_DATA[i,one]=="") HIGH_SAMPLING_ONLY<-HIGH_SAMPLING[!apply(HIGH_SAMPLING=="",MARGIN=one,any),] However, I keep getting an error stating that, Error in plot.window(...) : need finite 'ylim' values I tried converting it to a time series but still no joy in terms of plotting, I still get the same error. Does anyone know how to plot this time series data, all on one graph? Thanks -- Shane [[alternative HTML version deleted]]