5.23.48 style

set style { data | function } <style modifier> ...

The set style data command affects the default style that data from a file is plotted with. Likewise the set style function command changes the default style that functions are plotted with. Any valid style modifier can be used. For example:

set style data points
set style function lines linestyle 1

would cause datafiles to be plotted by default using points and functions using lines with the first defined linestyle.