funny error

I have a code using switch function and it gives the following error

supersonic_ob.cc:177: error:

jump to case label
supersonic_ob.cc:158: error: crosses initialization of ‘LaGenMatDouble delta_QQ’
What does it mean?

It means that the initializasion of LaGenMatDouble delta_QQ is done in one case and probably used in other...
You should place braces around case where the declaraton of the LaGenMatDouble delta_QQ is done

It's complaining because you might have writen code that looks like this, which wont print 42 when foo is 2 because it skipped over the line where foobar gets its value.
I thought that this usually only gave a warning though.

Code:

switch (foo) {
    case 1:
        int foobar = 21;
        cout << foobar;
    case 2:
        cout << foobar*2;
        break;
}

By putting braces around the code in case 1, foobar is no longer in scope in case 2 and the problem becomes obvious, and you definitely get an error.