is component part of statistical graph axis An axis is a line segment that is part of a statistical graph in which the position along the line corresponds to a numeric or categorical value. The value of a plotted geometric objects (e.g. point) can be obtained from the perpendicular projection of the position of the object onto the axis. Axis may also be associated with a textual description of what the values on the axis represents. SIO_000450 The left vertical and bottom horizontal lines with tickmarks in Graph 1 http://tinyurl.com/opwnvm directed line segment