The 16-Vector Algorithm for Computer Controlled Digital X-Y Plotter

Digital X-Y plotters are peripheral devices of digital computer installations and are used for directly plotting out the results of computations. Digital X-Y plotters normally use an 8-vector algorithm for plotting. This paper describes a superior 16-vector algorithm for digital plotting. The algorithm is based on the fact that, from a given starting point, the recording pen may be driven along any of the sixteen possible elementary vectors. The flow chart for the algorithm is given. It is shown that lines plotted using 16-vector algorithm have no error if their slopes are 0, ±1/2, ±1, ±2, and a. For lines of other slopes, the maximum error is limited to 4 step size. Thus the 16-vector algorithm described is much superior to the 8-vector algorithm. Implementation of this algorithm is also discussed in this correspondence.