Run this codes: plot( 1:20, type='l') lines( 0.5*1:20, col=2)
If you use par(new=T), this will call a new high-level graphic device, which is why the axes do not match. Alternatively, you can set ylim and pass the arguments to two plot functions: plot( rnorm(100), type='h', ylim=c(-3,3)) par(new=T, mar=c(3,4,3,3)) plot( 0.25*rnorm(100), type='l', col=2, ylim=c(-3,3), ylab='') axis(4) Jorgy Porgee wrote: > > Good day all, > > I'm trying to plot a continuous line plot, which is followed by two > forecast points eg. one forecast point is 12 months out, and another > 24 months out from the last date of the line plot. > > In my attempts so far, the second plot (the forecast points) is scaled > against a new axis scale, thus the two plots are not directly > comparable (I need the forecast points to be scaled according to the > existing y axis). > > An example is pasted below. Any ideas on how to achieve this would be > much appreciated. > > Thanking you in advance, > > George. > > # Sample dates >>xValues = seq.Date(as.Date("1990-01-31"),to=as.Date("1992-12-31"),by="month"); > > # Sample y value >> yValues<-NULL; >> yValues[1:length(xValues)]=seq(0.1,length=length(xValues)) > > # Plot the series as a line >> plot(xValues,yValues,type="l"); > > # Sample forecast dates that start from xValue's data point >> fcastDates=seq.Date(from=as.Date(xValues[length(xValues)]),length=12,by="month"); >> fcastDates > [1] "1992-12-31" "1993-01-31" "1993-03-03" "1993-03-31" "1993-05-01" > "1993-05-31" > [7] "1993-07-01" "1993-07-31" "1993-08-31" "1993-10-01" "1993-10-31" > "1993-12-01" > > # Sample forecast (we only want the forecast point to be displayed) > >> fcast<-NULL; fcast[1:length(fcastDates)]="NA"; fcast[length(fcast)]<-20; >> fcast > [1] "NA" "NA" "NA" "NA" "NA" "NA" "NA" "NA" "NA" "NA" "NA" "20" > > # Add the forecast plot to the original plot >> par(new=TRUE) >> plot(fcastDates,fcast,yaxt="n",xaxt="n",col="red") > Warning message: > In xy.coords(x, y, xlabel, ylabel, log) : NAs introduced by coercion > > # The second forecast > >> fcastDates2=seq.Date(from=as.Date(fcastDates[length(fcastDates)]),length=12,by="month"); >> fcastDates2 > [1] "1993-12-01" "1994-01-01" "1994-02-01" "1994-03-01" "1994-04-01" > "1994-05-01" > [7] "1994-06-01" "1994-07-01" "1994-08-01" "1994-09-01" "1994-10-01" > "1994-11-01" >> fcast2<-NULL; fcast2[1:length(fcastDates2)]="NA"; >> fcast2[length(fcast2)]<-15; >> par(new=TRUE);plot(fcastDates2,fcast2,yaxt="n",xaxt="n",col="blue") > Warning message: > In xy.coords(x, y, xlabel, ylabel, log) : NAs introduced by coercion > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > > -- View this message in context: http://www.nabble.com/How-do-I-plot-a-line-followed-by-two-forecast-points--tp24866692p24870219.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.