On 2/24/07, Robin Menneer <[EMAIL PROTECTED]> wrote: > > > > On 2/24/07, Andrew Price <[EMAIL PROTECTED]> wrote: > > On 24/02/07 17:54, Robin Menneer wrote: > > > I have a problem with fitting a curve to some data and would like help > > > please. The data are: > > > x=375, 375, 375, 355, 315, 268,195, 110, 0 > > > y=2500, 2150, 1920, 1600, 1250, 936, 624, 312, 0 > > > I need a program that will draw a line of best fit (for me to print) > > > according to different parameters,, especially log and power and find > the > > > best for me, and give me the equation for it. > > > > gnuplot seems like a good tool for this job. It's a tool with a wide > > range of options and commands so it can seem a bit daunting to use it > > for the first time (I should know, I used it for the first time today :)) > > > > Anyway, here's an example of how to do it (I'm assuming you've already > > installed the gnuplot package): > > > > Put your X and Y data in a text file in columns like: > > > > 375 2500 > > 375 2150 > > 375 1920 > > 355 1600 > > 315 1250 > > 268 936 > > 195 624 > > 110 312 > > 0 0 > > > > Then open a terminal and go to the directory with the data file in it > > and run gnuplot: > > > > $ cd /path/tomy/datafile/dir/ > > $ gnuplot > > > > Once you're in the gnuplot "shell", tell it to plot columns 1 and 2 as x > > and y respectively, giving the curve a title: > > > > gnuplot> plot "mydatafile.dat" using 1:2 title 'Data' smooth csplines > > > > Removing "smooth csplines" would make gnuplot plot each individual point > > without a curve, replacing "csplines" with "unique" joins the dots. A > > whole range more options can be found in the documentation [1]. > > > > If you want to plot the data to an image file, precede the plot command > > with something like these two commands: > > > > gnuplot> set terminal png > > gnuplot> set output 'mygraph.png' > > > > For a list of other output file types, just type 'set terminal' without > > an option. > > > > (Don't let the command line nature of this daunt you, it's pretty simple > > and tutorials like [2] and demos like [3] show you how powerful it can be) > > > > [1] http://www.gnuplot.info/docs/gnuplot.html > > [2] http://www.duke.edu/~hpgavin/gnuplot.html > > [3] http://www.gnuplot.info/demo/simple.html > > > > Hope this helps. > > > > -- > > Andy Price > > IRC: welshbyte > > http://andrewprice.me.uk > > Thanks - it does look daunting and I'll need a quiet afternoon (or day ?) > to puzzle my way through it. Many Thanks > Robin > > > -- > > ubuntu-uk@lists.ubuntu.com > > https://lists.ubuntu.com/mailman/listinfo/ubuntu-uk > > https://wiki.kubuntu.org/UKTeam/ > > > > I've spent all day looking at loading gnuplot and fityk as well as a dozen of other curvefitting packages on the web including xplot and have found none that are simple enouigh for me to install without my risking messing my memory/files up. Has nobody cleaned up a curvefiitting program in Ubuntu sufficiently for a thickie to run ?
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