I would like to create plot using gnuplot. The line width should be 3 in all plots. If I do it for one plot only this is done by:
set style line 1 linewidth 3
>
There are also other "line styles" that are set for all lines at once without index, e.g., for linespoints
:
set style data linespoints
plot '-', '-'
1, 1
2, 2
3, 3
e
1, 1
2, 4
3, 9
e
Have a look at the "Style" section of the TOC of the manual http://www.gnuplot.info/docs_5.0/gnuplot.pdf for other things that can be set by default.