On Thu, Mar 27, 2008 at 18:45:21 -0400, H.S. wrote: > Florian Kulzer wrote:
[...] >> For a small number of colors something like this is may be acceptable: >> >> # START >> unset key >> set xrange [0:1] >> set yrange [0:1] >> set multiplot >> plot "3cols.dat" using ($1):($3==1 ? $2 : 1/0) lt 1 >> plot "3cols.dat" using ($1):($3==2 ? $2 : 1/0) lt 2 >> plot "3cols.dat" using ($1):($3==3 ? $2 : 1/0) lt 3 >> plot "3cols.dat" using ($1):($3==4 ? $2 : 1/0) lt 4 >> unset multiplot >> # END >> >> To scale this up sensibly for many more colors, put the plot command >> into a separate file that is called as a subroutine from the main >> program. In this subroutine you can use a counter variable for both the >> $3 comparison and the lt assignment. After the plot command you can >> increment the counter and use the if/reread trick (see the manual) to >> make sure that the subroutine is re-executed as many times as is >> necessary to loop over all the colors. > > Please see my earlier post. Using splot may be a better solution since I > did not have to do any comparisons there. Yes, maybe. > But your example is very > interesting and lists some neat tricks, and it uses the 'plot' instead > of 'splot'. However, I have a little doubt. You are differentiating the > plotted points with the linetype, "lt", right? Doesn't lt cycle back in > gnuplot after a certain number of plots? Yes, it does, but the number of easily distinguishable colors is limited, too. With the above approach you can at least vary the point or line style if you have to use similar colors for more than one subset of the data. > I guess how many such types are > available can be determined using the 'test' command in gnuplot. Before > plotting, I would need to increase that number somehow, if possible. I am not sure if this is easily possible or if it makes sense (see above). I tend not to spend time wrestling with gnuplot's style and color defaults, I simply produce an EPS output file with the default settings and then I modify the EPS file directly. Colors and line/point styles in gnuplot's EPS files can easily be changed by simple sed operations (which can be embedded as external commands in the gnuplot script). > plotting, I would need to increase that number somehow, if possible. As > you correctly mentioned, this approach is fine for small number of > colors. One more thing worth mentioning is that the subroutine trick can also be used to loop over the columns of a dataset (using the "column" command), for example if you have a data file with one common x-axis and 100 y-datasets (columns) that you want plot in the same graph. (Or can the plot command do this automatically these days?) -- Regards, | http://users.icfo.es/Florian.Kulzer Florian | -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
