Questions 9

1. How do you pass your integrand (= the function that is to be integrated) to gsl_integration_qags rutine?
2. What are the arguments epsabs, epsrel and abserr (correspondingly the 4th, 5th and last argument) of gsl_integration_qags rutine?
3. What is the return type of gsl_integration_qags and what does it return?
4. How does gsl_integration_qags return the calculated result?
5. Does gsl_integration_qags estimate the error of the calculated result?
6. Suppose you integrand does not take any extra parameters: what do you do then with the .params member of the corresponding gsl_function structure?
7. What is the limit argument (the 4th argument) of the gsl_integration_qagi rutine?
8. What is the argument of the gsl_integration_workspace_alloc function?
9. Do you need to free any memory having finished with your gsl_integration_qags integrations?
10. Suppose your C-function returns an integer value, like gsl_integration_qags function, which you would normally call as

    int status = gsl_integration_qags(arguments);
    

    can you call the function simply as

    gsl_integration_qags(arguments);
    

    ?
11. Suppose you need to calculate an integral with a given requirement to the absolute error and the relative error is irrelevant. How do you then set up your accuracy parameters of gsl_integration_qags routine?
12. Suppose your integration routine returned the status GSL_EDIVERGE. What does that mean?