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Re: [LUG] Openoffice help

 

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


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