i want to implement an iterative algorithm that needs to solve one LLS-problem per iteration. The system matix A remains the same over all iterations, only b changes. The function "gels" does exactly what i need, but itperforms thea call to "geqrf" on every call.For performance reasons i would like to do the QR factorisation only once at the beginning of the algortithm and only change b from one iteration to the next.
Is this possible with gels? What happens if i provide a result from geqrf as parameter A to gels?
Which combination of functions do is have to use?