Maximum Entropy and Bayesian Methods Fundamental Theories of Physics An International Book Series on The Fundamental Theories of Physics: Their Clarification. Development and Application Editor: ALWYN V AN DER MERWE University ofD enver. U.SA. Editorial Advisory Board: ASIM BARUT, University of Colorado. U.S.A. HERMANN BONDI, University of Cambridge. U.K. BRIAN D. JOSEPHSON, University of Cambridge. U.K. CLIVE KILMIS1ER, University ofL ondon. U.K. GUNTER LUDWIG, Philipps-Universitiit. Marburg. F R.G. NATHAN ROSEN, Israel Institute of Technology. Israel MENDEL SACHS, State University ofN ew York at Buffalo. U.s.A. ABDUS SALAM, International Centre for Theoretical Physics, Trieste. Italy HANS-JORGEN TREDER, Zentralinstitut fur Astrophysik der Akademie der Wissenschaften. GD.R. Maximum Entropy and Bayesian Methods Cambridge, England, 1988 edited by 1. Skilling Department ofA pplied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, u.K. Springer-Science+Business Media, B. V. Library of Congress Cataloging in Publication Data Maximum Entropy Workshop (8th: 1988: St. John's College) Maximum entropy and Bayesian methods, Cambridge, U.K., 1988 edited by J. Skilling. p. cm. -- (Fundamental theories of physiCS) Inc 1u des index. Proceedings of the 8th MaxEnt Workshop held at St. John's College, Cambridge, England, August 1-5, 1988, 1. Entropy (Information theory)--Congresses. 2. Bayesian statistical decision theory--Congresses, I. Skilling, J. (John) II. Title. III. Series. 0370.M385 1988 001.53'9--dc19 89-2480 printed on acid free paper This work relates to Department of Navy Grant NOOOl4-88-J-1126 issued by the Office of Naval Research. The United States Government has a royalty-free license throughout the world in all copyrightable material contained herein." ISBN 978-90-481-4044-2 ISBN 978-94-015-7860-8 (eBook) DOI 10.1007/978-94-015-7860-8 Softcover reprint of the hardcover 1st edition 1989 All Rights Reserved @ 1989 by Springer Science+Business Media Dordrecht Originally published by Kluwer Academic Publishers in 1989. No part of the material protected by this copyright notice may be reproduced or utilized in any form or by any means, electronic or mechanical including photocopying, recording or by any information storage and retrieval system, without written permission from the copyright owner. Dedication To the ideal of rational inference PREFACE The "8th MaxEnt Workshop", to give it its short name, was held in St. John's College, Cambridge, England, on August 1 - 5, 1988, and this Volume of 55 papers records the Proceedings. History repeats itself in many ways. All ancient civilisations evolved some core of basic practical mathematics, but it was the Greeks who insisted upon superior intellectual standards. It was the Greeks who invented the world of axioms and theorems. They invented and formalised the central idea of logical proof, so that assent to axioms perforce requires assent to their consequences, however long the chain of reasoning involved. Conversely, any attack on the consequences becomes an attack upon the axioms, which are usually much simpler to discuss. This power and beauty swept cruder mathematics aside for ever. An echo of this occurs in our own century. We live in a complicated world, and our procedures for learning from observations are codified as the subject of statistics. Often enough, we are concerned with difficult problems, and a variety of more or less ad hoc practical techniques has evolved to deal with them. Yet there is an inner logic to the practice of inference, which leads inevitably to the use of quantified probabilities, manipulated by Bayes' theorem and assigned by the principle of maximum entropy (MaxEnt). Those who live by this logic are called Bayesians. Because of their inner certainty of methodology, they are sometimes perceived as religious fundamentalists - but that does not in itself mean that they are wrong. The Bayesian/MaxEnt church is alive and well, and has its own calendar of saints (and devils). Foreshadowed by the MIT meeting of 1978, the first formal assembly was held ~n Laramie, Wyoming in June 1981. It was my particular pleasure to attend that first "Workshop on Maximum Entropy and Bayesian Methods in Applied Statistics", organised by Ray Smith and Tom Grandy, who have since become lasting friends of mine. MaxEnt was then beginning to grow beyond the confines of statistical thermo dynamics, where it had enjoyed a certain degree of protection afforded by the abstract nature of the subject, by the conveniently large value of Avogadro's number, and by the demonstrable success of its predictions. Bayes' theorem, likewise, was beginning to break free of the suffocating weight of "orthodox" statistics, substantially aided by the brilliant logic and polemic of Edwin Jaynes. Each summer since 1981 has seen a further meeting in the series. Each has been notable for some new inspiration and application, for the particular strength of rational thought is that it works. More and more quickly, inference problems in all sorts of disciplines are being brought within the purview of Bayesian/MaxEnt analysis. The 1988 meeting, held in St. John's College, Cambridge, had a particularly appropriate venue. Sir Harold Jeffreys, who vii viii PREFACE cared deeply about rational inference throughout a long working life, is the Senior Fellow. Prof. Edwin T. Jaynes, whose influence on the subject has been so profound, is also connected with St. John's, having been Overseas Fellow in 1983/4. On a lesser plane, my own introduction to MaxEnt was a lunch-time conversation in College with my mentor, friend and colleague, Steve Gull. Being the first of the workshops to be held in Europe, this meeting attracted over 100 delegates, from industry and from defence establishments as well as from academia. A central topic such as inference can be expected to touch a number of other subjects, but even the organisers were surprised by the variety of topics which were offered and presented, from philosophy to floods, from biology to astronomy, and with references ranging from New Left Publications to Acta Crystallographica. Profound thanks are due to our financial sponsors, who provided the funds needed to invite distinguished overseas speakers whilst keeping the fees low enough for the academic pocket. The United States Navy Office of Naval Research maintained its valued connection with the workshop series through its grant N00014-88-J-1126, and industrial support was provided by E.I. DuPont Company Central Research and Development, ICI Chemicals and Polymers Group, Glaxo Group Research Limited, British Petroleum pic, and Maximum Entropy Data Consultants Limited. Thanks are also due to St. John's College, which provided such appropriate and attractive facilities, and whose staff were unfailingly generous with their time and effort. Not least, I wish to thank in particular my wife and son, Jennifer and Martin Skilling, for their secretarial and organisational help, which contributed so much to the smooth running of the meeting. Thank you, all. The authors of the papers published here also deserve my editorial thanks for producing their papers so well and so promptly. In the interests of quick publication, the workshop is continuing the recent practice of using camera-ready copy. Because interest continues to grow, the workshops are currently being formally organised on a continuing basis, with a permanent organising committee, and their Proceedings are henceforward to be published by Kluwer Academic Publishers under the generic title "Maximum Entropy and Bayesian Methods (location) (year)". It is hoped that each successive volume will continue to capture something of the excitement and vitality of current research. Lastly, I wish as Editor to dedicate this Volume, not to any particular individual, but to that transcending ideal to which we try to aspire - the ideal of rational inference. St. John's College John Skilling Cambridge January 1989 CONTENTS Preface V11 Tutorial E.T. Jaynes Clearing up mysteries -The original goal C.R. Smith, G. Erickson From rationality and consistency to Bayesian probability 29 1. Skilling Classic maximum entropy 45 S.F. Gull Developments in maximum entropy data analysis 53 W.T. Grandy, Jr. The three phases of statistical dynamics 73 A.l.M. Garrett Bell's theorem, inference and quantum transactions 93 Philosophy A.J.M. Garrett Probability, philosophy and science: a briefing for Bayesians 107 Statistical thermodynamics & Quantum mechanics R.D. Levine The statistics of quantum mechanical wavefunctions 117 R. Balian Justification of the maximum entropy criterion in quantum mechanics 123 CONTENTS J.P. Dougherty Approaches to non-equilibrium statistical mechanics 131 D.A. Drabold, A.E. Carlsson, P.A. Fedders Applications of maximum entropy to condensed matter physics 137 R. Collins, T. Ogawa and T. Ogana Problems of maximum-entropy formalism in the statistical geometry of simple liquids 143 Physical measurement techniques G.l. Daniell, 1.A. Potton Liquid structure factor detem1ination by neutron scattering -some dangers of maximum entropy 151 R.l. Papoular, A.K. Livesey Quasielastic neutron scattering data evaluation using the maximum entropy method 163 R. T. Constable, R.M. Henkelman Maximum entropy reconstruction in magnetic resonance imaging 175 N.A. Farrow, F.P. Ottensmeyer Solution of autocorrelation function constrained maximum entropy problems using the method of simulated annealing 181 A.K. Livesey, 1-C. Brochon, P. Licinio Solution of Laplace transform equations (sum of exponentials) by maximum entropy 191 A. Mohammad-Djafari, G. Demoment Maximum entropy and Bayesian approach in tomographic image reconstruction and restoration 195 Crystallography S. Steenstrup, S.W. Wilkins Maximum-entropy-based approaches to X-ray structure determination and data processing 203 R.K. Bryan Maximum entropy in crystallography 213