2
$\begingroup$

How should I find out what the default value of Accuracy and Precision is in the NDSolve? I have a pde that when I asked it to solve for me the equation with a special Accuracy and precision it gave me back an error, but if I live the NDSolve with its default. It would solve it. I don't know how to find the value of accuracy and precision. another basic question which have is about the meaning of the Accuracy and precision. I know the meaning in general from high school, but the problem is that I do not know the meaning of Accuracy->15, does it calculate it for 15 decimal number or what?

$\endgroup$
  • 1
    $\begingroup$ You can do Options[NDSolve] and see the default values. It says Automatic for some. Then go to each and looks at its help. For Accuracy it says AccuracyGoal->Automatic normally yields an accuracy goal equal to half the setting for WorkingPrecision and for PrecisionGoal it says ->Automatic normally yields a precision goal equal to half the setting for WorkingPrecision SO they depend on setting for WorkingPrecision Then you look at help for WorkingPrecision $\endgroup$ – Nasser Oct 8 '14 at 16:41
2
$\begingroup$

Following @Nasser's comment, both defaults are $MachinePrecision/2, 7.97729 in my case.

Related post: Is manual adjustment of AccuracyGoal and PrecisionGoal useless?

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.