[ Date Index ] [ Thread Index ] [ <= Previous by date / thread ] [ Next by date / thread => ]
On Mon, 2009-12-14 at 16:13 +0000, Terry Hill wrote: > > You need to plot the graph as x-y, rather than line - this will > > correctly space the x values. (You'll also need to select your x-values > > as otherwise they will be spaced 1, 2, 3, 4 etc). > > > > Moving the x axis to the bottom of the plot requires you to select the > > x-axis, right click and go to object properties, then the positioning > > tab. Select "start" from the "Axis Line - Crosses other axis at" drop > > down. > > > > I've attached your ods file with these changes made. > > Well that's brilliant, I've just cracked the gnuplot route (it was > down to defining the axis slightly differently, probably a windows > thing) and you've also shown me how to do the same thing in > openoffice. Today has been very educational, I love gnuplot already > now I'm getting used to it (well as much as you *can* love something > that plots graphs...). > > I love this list, thanks a ton everyone! Anyone fancy wrinting 2000 > words for me now for my study skills folder? :D > You're welcome. By the way, I also noticed that you wanted to add a vertical line where your plot crossed zero. That's a slightly deeper question, as The OOo plot is using straight lines to join the points, and the estimated zero point would probably lie on a fitted curve. If you do need to do that, you would probably need to use a linear model in a package like R, and then add the line based on the estimated zero point. Looking at your data it could be modelled by a quadratic (e.g. y ~ f[x, x^2]). You would, of course, fit the curve to all the data, rather than the averages for each molarity. Otherwise you could estimate the zero point by "eye-balling" it. Phil -- The Mailing List for the Devon & Cornwall LUG http://mailman.dclug.org.uk/listinfo/list FAQ: http://www.dcglug.org.uk/linux_adm/list-faq.html