The length of the sample line can be controlled by samplen. The sample
length is computed as the sum of the tic length and sample_length
times the
character width. samplen also affects the positions of point samples in
the key since these are drawn at the midpoint of the sample line, even if
the sample line itself is not drawn.
The vertical spacing between lines is controlled by spacing. The spacing
is set equal to the product of the pointsize, the vertical tic size, and
vertical_spacing
. The program will guarantee that the vertical spacing is
no smaller than the character height.
The width_increment
is a number of character widths to be added to or
subtracted from the length of the string. This is useful only when you are
putting a box around the key and you are using control characters in the text.
gnuplot simply counts the number of characters in the string when computing
the box width; this allows you to correct it.