2PLOT: plot arc - draw an arc Usage: plot arc [ [ ]] draws a circle, an ellipse, or part of a circle or ellipse with the center at (x,y), and half axes a and b. If b is omitted, a circle with radius a (measured in the x-direction) is drawn. Optionally, only the part of the ellipse starting and ending with phase angles f1 and f2, respectively, is drawn. The phase angle is 0 on the positive x-axis and increases counterclockwise. This command can also be used in list mode, where the parameters are vector expressions.