Such a line has for abscissa the distance of a load from one end of a girder, and for ordinate the bending moment or shear at any given section, or on any member, due to that load.
If we construct a curve with x as abscissa and X as ordinats, this work is represented, as in J.
We take a fixed line OX, usually drawn horizontally; for each value of X we measure a length or abscissa ON equal to x.L, and draw an ordinate NP at right angles to OX and equal to the corresponding value of y .
The angle cp is termed the eccentric angle, and is geometrically represented as the angle between the axis of x (the major axis of the ellipse) and the radius of a point on the auxiliary circle which has the same abscissa as the point on the ellipse.
A curve with I as abscissa and u as ordinate is called the curve of velocities or velocity-time curve.
Thus PS (or OR) is the abscissa of P. The word appears for the first time in a Latin work written by Stefano degli Angeli (1623-1697), a professor of mathematics in Rome.
The ordinate of the trapezette will be denoted by u, and the abscissa of this ordinate, i.e.
The relation between x and t in any particular case may be illustrated by means of a curve constructed with I as abscissa and x as ordinate.