[ https://issues.apache.org/jira/browse/MATH-204?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Brent Worden resolved MATH-204. ------------------------------- Resolution: Fixed Fix Version/s: 1.3 SVN 654100. added root checks for the endpoints. > BrentSolver throws IllegalArgumentException > -------------------------------------------- > > Key: MATH-204 > URL: https://issues.apache.org/jira/browse/MATH-204 > Project: Commons Math > Issue Type: Bug > Affects Versions: 1.2 > Environment: Win XP > Reporter: Mick > Assignee: Brent Worden > Priority: Minor > Fix For: 1.3 > > > I am getting this exception: > java.lang.IllegalArgumentException: Function values at endpoints do not have > different signs. Endpoints: [-100000.0,1.7976931348623157E308] Values: > [0.0,-101945.04630982173] > at org.apache.commons.math.analysis.BrentSolver.solve(BrentSolver.java:99) > at org.apache.commons.math.analysis.BrentSolver.solve(BrentSolver.java:62) > The exception should not be thrown with values [0.0,-101945.04630982173] > because 0.0 is positive. > According to Brent Worden, the algorithm should stop and return 0 as the root > instead of throwing an exception. > The problem comes from this method: > public double solve(double min, double max) throws > MaxIterationsExceededException, > FunctionEvaluationException { > > clearResult(); > verifyInterval(min, max); > > double yMin = f.value(min); > double yMax = f.value(max); > > // Verify bracketing > if (yMin * yMax >= 0) { > throw new IllegalArgumentException > ("Function values at endpoints do not have different signs." + > " Endpoints: [" + min + "," + max + "]" + > " Values: [" + yMin + "," + yMax + "]"); > } > // solve using only the first endpoint as initial guess > return solve(min, yMin, max, yMax, min, yMin); > } > One way to fix it would be to add this code after the assignment of yMin and > yMax: > if (yMin ==0 || yMax == 0) { > return 0; > } -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.