Method and appartus for making hard copy records of curves including

Abstract

A line scan cathode ray tube (CRT) recorder generates a hard copy record of a curve from stored data representing the X-Y coordinates of a series of sample points along the curve. The curve may be described mathematically by a multi-valued function. One pass of the recording media past a linear sweeping CRT beam records the entire curve in a predetermined number of recording sweeps. The distance (.DELTA.X and .DELTA.Y, respectively) between each and every X.sub.n, Y.sub.n and the next successive stored sample point X.sub.n+1, Y.sub.n+1 is determined prior to each recording sweep of the beam and these distances, .DELTA.X and .DELTA.Y, are divided by a predetermined number to give a factor interpolating the distance between successively stored data points (X.sub.n and X.sub.n+1 and Y.sub.n and Y.sub.n+1). Each recording sweep of the beam represents a band (in the X-axis direction, for example) on the recording media of finite width extending from one recording sweep position up to, but not including, the next recording sweep position. The X-Y coordinates of each sample point are successively incremented by the interpolative value .DELTA.X/n and .DELTA.Y/n, respectively, where 'n' equals the number of interpolative steps. The Y-axis coordinate positions of the interpolative value (Y+ n.DELTA. Y/n!) are stored corresponding to the interpolative X-axis coordinate (X+ n.DELTA. X/n!) positions within the finite band to be recorded. As the beam sweeps along a given X-axis position, it records a short line for each stored Y-axis position.