SOFTWARE—PRACTICE AND EXPERIENCE, VOL. 21(1 1), 1129-1164 (NOVEMBER 1991) Graph Drawing by Force-directed Placement THOMAS M. J. FRUCHTERMAN* AND EDWARD M. REINGOLD Department of Computer Science, University of Illinois at Urbana-Champaign, 1304 W. Springfield Avenue, Urbana, IL 61801-2987, U.S.A. SUMMARY We present a modification of the spring-embedder model of Eades [ Congresses Numerantium, 42