You can generalize the approach by using something like: ... ylim = c(0, max(DF$TACC, DF$Catch) * 1.1) ...
That would allow you to use the max value of the two columns, multiplied by a fudge factor, which you can adjust as needed. In this case, increasing the y axis range by 10% to make room. HTH, Marc on 01/07/2009 02:31 PM jimdare wrote: > Thanks Marc, that has helped a lot. Say, for example, in a situation where I > can't find out the highest value, is there any way to get R to automatically > detect this and adjust the axis accordingly? I am planning to do this for > many different stocks at once and dont wan't to have to define the highest > value for each. I could set a standard axis value based on the max values > of all stocks, however the detail will be lost for many of the less > exploited species. > > > Marc Schwartz wrote: >> on 01/06/2009 09:07 PM jimdare wrote: >>> Hi Everyone, >>> >>> Have created a bar plot of the data below using the following code: >>> barplot(TACC,space=0,names.arg=Year). I now want to add a series of >>> connected points to represent the catch. I tried to do this using >>> line(Catch) or points(Catch), however both of these commands result in >>> each >>> data point being aligned with the right edge of each bar. I need them to >>> be >>> solid points in the centre of each bar, and for each point to be >>> connected >>> to its neighbour by a line. Another issue I have is when the points >>> exceed >>> the values for the bar graph (e.g. in 2004 and 2005 catch>TACC) R seems >>> to >>> cut them off, I need the axis to be expanded so they can be seen. I'm >>> sure >>> these are relatively simple problems but I am really stuck. Thanks very >>> much for all your help, it is much appreciated. >>> >>> James >>> >>> DATA: >>> >>> Year Species Stock TACC Catch >>> 1 2001 ORH OR1 5000 4687 >>> 2 2002 ORH OR1 6000 3215 >>> 3 2003 ORH OR1 7000 6782 >>> 4 2004 ORH OR1 9000 10000 >>> 5 2005 ORH OR1 9000 12000 >> One key point to note is that barplot() returns the bar midpoints. This >> is noted in the help for barplot(). The bars are not centered on integer >> axis values, so you need the returned values to place additional >> annotation in the proper location relative to the bars. >> >> The other thing is to set the range of the y axis using the maximum >> value in Catch, plus some fudge, so that the plot covers both sets of >> data and has enough room for the additional points. >> >> Thus, presuming that your data is in a data frame called 'DF': >> >> mp <- barplot(DF$TACC, space = 0, names.arg = DF$Year, >> ylim = c(0, 13000)) >> >> # Now use lines() to add Catch >> lines(mp, DF$Catch, type = "b", pch = 19) >> >> See ?barplot, ?lines and ?points for more information. >> >> HTH, >> >> Marc Schwartz >> ______________________________________________ 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.
