John Kane wrote: > I clearly spoke too soon. > > With the actual data I am not getting sensible x-axis > units. The program with the actual data below. Graph > output is here: > http://ca.geocities.com/jrkrideau/R/hd.png . > > I seem to be getting only a single entry for the > x-axis of "2007". However dates range from > First Date Last Date > "2006-09-26" "2007-11-10" > > I must be missing something blindingly obvious but I > don't see it. > > Thanks for any suggestions. > > > Actual data and test program > ================================================ > mydata <- > read.table("http://ca.geocities.com/jrkrideau/R/heartdata.txt", > sep="\t", > header=FALSE) > mydata[,1] <- as.Date(mydata[,1],"%m/%d/%y") > names(mydata) <- Cs(dates, sy,dys,pulse, weight) > minmax <- c(max(mydata[,2]),min(mydata[,2]), > max(mydata[,3]),min(mydata[,3])) > names(minmax) <- c("maxsys", "minsys", "maxdsy", > "mindys") ; minmax > > min.max.dates <- c(min(mydata[,1]), max(mydata[,1])) > names(min.max.dates) <- c("First Date", "Last Date"); > min.max.dates > > ss <- lm(mydata[,2]~mydata[,1]) > plot(mydata[,1],mydata[,2], xlab="Dates", ylab="Blood > pressure", > ylim=c(minmax[4], minmax[1]), col= "red", > type="l") > abline (ss, col ="yellow") > dd <- lm(mydata[,3]~mydata[,1]) > points(mydata[,1], mydata[,3], type="l", col="blue" ) > abline(dd, col= "yellow", lwd=2) > > > Hi John,
It can be done like this: plot(mydata[,1],mydata[,2], xlab="Dates", ylab="Blood pressure",ylim=c(minmax[4], minmax[1]), col= "red", type="l",xaxt="n") ... axisdates<-c("2006-11-01","2007-01-01","2007-03-01", "2007-05-01","2007-07-01","2007-09-01","2007-11-01") staxlab(at=as.Date(axisdates),labels=axisdates) Jim ______________________________________________ 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.