Arrows

The 2D arrows style draws an arrow with specified length and orientation angle at each point (x,y). Additional input columns may be used to provide variable (per-datapoint) color information or arrow style. It is identical to the 2D style with vectors except that each the arrow head is positioned using length + angle rather than delta_x + delta_y. See with vectors.
4 columns:  x  y  length  angle

The keywords with arrows may be followed by inline arrow style properties, a reference to a predefined arrow style, or arrowstyle variable to load the index of the desired arrow style for each arrow from a separate column.

length > 0 is interpreted in x-axis coordinates. -1 < length < 0 is interpreted in horizontal graph coordinates; i.e. |length| is a fraction of the total graph width. The program will adjust for differences in x and y scaling or plot aspect ratio so that the visual length is independent of the orientation angle.

angle is always specified in degrees.

Copyright 1986 - 1993, 1998, 2004 Thomas Williams, Colin Kelley
Distributed under the gnuplot license (rights to distribute modified versions are withheld).