Four-Point Smoothing With FPP-12

This document describes a program for the PDP-12 computer that performs data smoothing using the FPP-12 Floating Point Processor. The routine takes an array of 4095 data points and fits them to a four-point least squares quadratic, advancing one point at a time. The program is optimized for speed and efficiency, operating on data stored as single 12-bit words rather than the typical 36-bit floating-point format, and utilizing single-word addressing to conserve memory. Performance testing demonstrates that this implementation is significantly faster than the standard DEC software floating-point package, and it allows for visual monitoring of the smoothing process on the CRT due to its parallel operation with the PDP-12 CPU. A more advanced 8-point smoothing routine is available as DECUS No. 12-73.