🚀 go-pugleaf

In article <92Dec17.174419.27750@acs.ucalgary.ca> mgh@hobbes.phys.ucalgary.ca (Mike Henderson) writes:
>I am trying to solve a set of 8 nonlinear equations in 8 unknowns.
>I have tried the Newton-Raphson technique given in NR (I know
>roughly what the solution should be) but havent had much luck. Are
>there any more robust methods to choose from?
>
>Mike Henderson
>Dept. of Physics and Astronomy
>University of Calgary
>mgh@hobbes.phys.ucalgary.ca
Is it possible in your case to calculate the analytical derivative?
If so ::::---->
I had similar kinda problem.  I had 10 NLE's and 12 variables 
Initially it was not working because of a few errors in the 
calculations of the analytical derivatives required for the 
Jacobian.  You can check the derivatives by calculating the 
numerical derivatives and they must be very close.If there
is large difference in numerical and analytical derivatives then
you are doing some mistake in calculation of the analytical
derivative or may be some other simple problem such as matrix
size.  Check if your analytical and numerical derivatives are same
I hope it will work because it is working in my case when
the numerical and analytical derivatives were very nearly equal(3 digits


ravi