**1. NAME AND TITLE**

BAYES: User's Guide for A General-Purpose Computer Code System for Fitting a
Functional Form to Experimental Data.

**2. CONTRIBUTOR**

Oak Ridge National Laboratory, Oak Ridge, Tennessee.

**3. CODING LANGUAGE AND COMPUTER**

Fortran IV; PDP-10.

**4. NATURE OF PROBLEM SOLVED**

BAYES is intended as a user's guide for a general-purpose computer program, BAYES, to solve "Bayes' equations" for updating parameter values, uncertainties, and correlations. Bayes' equations are derived from Bayes' theorem, using linearity and normality assumptions.

BAYES can be used to solve Bayes' equations for an arbitrary problem, much as one would use
a generalized least-squares solver.

**5. METHOD OF SOLUTION**

Solving the iterative form of the Bayes' equations is equivalent to solving a matrix equation of the
form AX = Y, where A is an L x L symmetric matrix, L being the number of data points and Y a
column matrix. A scaling operation is performed on the matrix A to ensure reasonable accuracy in
the solution.

**6. RESTRICTIONS OR LIMITATIONS**

None noted.

**7. TYPICAL RUNNING TIME**

No study has been made by RSIC of typical running times for BAYES.

**8. COMPUTER HARDWARE REQUIREMENTS**

BAYES is operable on the PDP-10 computer.

**9. COMPUTER SOFTWARE REQUIREMENTS**

A Fortran IV compiler is required.

**10. REFERENCE**

N. M. Larson, "User's Guide for BAYES: A General Purpose Computer Code for Fitting a
Functional Form to Experimental Data," ORNL/TM-8185 (August 1982).

**11. CONTENTS OF CODE PACKAGE**

Included are the referenced document and one (1.2MB) DOS diskette which contains the source
code and sample problem input and output.

**12. DATE OF ABSTRACT**

February 1984.

**KEYWORDS**: INTERACTIVE, ON-LINE; UNCERTAINTY ANALYSIS