A root finding procedure should stop when one of the following conditions is true:
The handling of these conditions is under user control. The functions below allow the user to test the precision of the current result in several standard ways.
This function tests for the convergence of the sequence by comparing the
last step dx with the absolute error epsabs and relative
error epsrel to the current position x. The test returns
GSL_SUCCESS
if the following condition is achieved,
for each component of x and returns GSL_CONTINUE
otherwise.
GSL_SUCCESS
if the
following condition is achieved,
and returns GSL_CONTINUE
otherwise. This criterion is suitable
for situations where the the precise location of the root, @math{x}, is
unimportant provided a value can be found where the residual is small
enough.