Fabulous, it works great. I didn't know about approx(). Thank you
-----Original Message----- From: Gabor Grothendieck [mailto:[EMAIL PROTECTED] Sent: Friday, July 01, 2005 1:54 PM To: Doran, Harold Cc: r-help@stat.math.ethz.ch Subject: Re: [R] Lines for plot (Sweave) On 7/1/05, Doran, Harold <[EMAIL PROTECTED]> wrote: > Dear List: > > I am generating a series of plots iteratively using Sweave. In short, > a dataframe is subsetted row by row and variable graphics are created > conditional on the data in each row. In this particular case, this > code ends up generating 17,000 individual plots. > > In some cases, all student data (this is working with student > achievement data) are available and my code below works very well in > the sense that a line connects all points. However, in some cases > there are missing data and I need to modify my code so that lines are > connected through all points even when data are missing. > > Here is a snip of relevant code. In the actual program, the data in > stu.vector and avg.vector are obtained from the dataframe as the > programs loops through each row. > > stu.vector<-c(2500, 2510, NA , 2600) > avg.vector<-c(2635, 2589, 2628, 2685) > x <- c(0,1,2,3) > graph.min <- min(stu.vector,avg.vector ,na.rm=TRUE)-150 graph.max <- > max(stu.vector,avg.vector ,na.rm=TRUE)+150 plot(x, stu.vector, > ylim=c(graph.min,graph.max), xlab=" ", ylab="Scaled Score", xaxt='n', > pch=2, col='blue', main="Math Growth Rate") points(x, avg.vector, > pch=1, col='red') lines(x, stu.vector, lty=1, col='blue') lines(x, > avg.vector, lty=3, col='red') > > If the NA did not exist in the object stu.vector then all points would > be connected with lines. However, in some cases data are missing and I > need to connect the data in stu.vector with lines. So in this case, > the line would connect points 1 and 2, and then 2 and 4 even though > point 3 is missing. Replace the first lines statement with: lines(approx(x, stu.vector), lty=1, col='blue') ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html