As another practical example of the use of the template file approach, consider writing a general program for solving a system of equations of the form:
using Newton's method [32]. A bold typeface is again used to denote a vector.
The system of iterates can be written as:
where  denotes the
Jacobian matrix and 
 is a given set of initial values used to start
the iteration process. 
 denotes the inverse of 
 and the
superscript 
 denotes evaluation at iterate 
. The
iterative process is continued until some stopping criteria are satisfied at
iteration
itmax. When the system to be solved is scalar valued, 
 is
simply the reciprocal of 
. For practical implementation,
(
) is rewritten at each iteration as:
where  satisfies
The linear system (
) is typically
solved using LU decomposition of the Jacobian matrix at each iteration. The
value of  thus obtained is substituted into (
)
to obtain .