Syntax:
set style ellipse {units xx|xy|yy} {size {graph|screen} <a>, {{graph|screen} <b>}} {angle <angle>} {clip|noclip}
This command governs whether the diameters of ellipses are interpreted in the same units or not. Default is xy, which means that the major diameter (first axis) of ellipses will be interpreted in the same units as the x (or x2) axis, while the minor (second) diameter in those of the y (or y2) axis. In this mode the ratio of the ellipse axes depends on the scales of the plot axes and aspect ratio of the plot. When set to xx or yy, both axes of all ellipses will be interpreted in the same units. This means that the ratio of the axes of the plotted ellipses will be correct even after rotation, but either their vertical or horizontal extent will not be correct.
This is a global setting that affects all ellipses, both those defined as objects and those generated with the plot command, however, the value of units can also be redefined on a per-plot and per-object basis.
It is also possible to set a default size for ellipses with the size keyword. This default size applies to data plots with only 2 columns of data (x,y) and to function plots. The two values are interpreted as the major and minor diameters (as opposed to semi-major and semi-minor axes) of the ellipse.
The default is "set style ellipse size graph 0.05,0.03".
Last, but not least it is possible to set the default orientation with the angle keyword. The orientation, which is defined as the angle between the major axis of the ellipse and the plot's x axis, must be given in degrees.
Clip clips the ellipse at the plot boundaries, noclip disables this. Default is clip.
For defining ellipse objects, see set object ellipse (p. ); for the 2D plot style, see ellipses (p. ).