Editing Conjugate gradient method (section)

====Restarts====
We note that <math>\mathbf{x}_{1}</math> is computed by the [[Gradient descent#Solution of a linear system|gradient descent]] method applied to <math>\mathbf{x}_{0}</math>. Setting <math>\beta_{k}=0</math> would similarly make <math>\mathbf{x}_{k+1}</math> computed by the [[Gradient descent#Solution of a linear system|gradient descent]] method from <math>\mathbf{x}_{k}</math>, i.e., can be used as a simple implementation of a restart of the conjugate gradient iterations.<ref name="BP" /> Restarts could slow down convergence, but may improve stability if the conjugate gradient method misbehaves, e.g., due to [[round-off error]].