A linestyle is a temporary association of properties linecolor, linewidth,
dashtype, and pointtype. It is defined using the command set style line.
Once you have defined a linestyle, you can use it in a plot command to control
the appearance of one or more plot elements. In other words, it is just like
a linetype except for its lifetime. Whereas linetypes are permanent (they
last until you explicitly redefine them), linestyles last until the next
reset of the graphics state.
Examples:
# define a new line style with terminal-independent color cyan,
# linewidth 3, and associated point type 6 (a circle with a dot in it).
set style line 5 lt rgb "cyan" lw 3 pt 6
plot sin(x) with linespoints ls 5 # user-defined line style 5
