[SciPy-user] fsolve help

[demarchi]

John Hassler <hasslerjc <at> adelphia.net> writes:

> 
> Actually, they're two different problems.  Assuming that a solution
> exists, having the same number of equations as unknowns allows you to 
> find the "exact" solution (that is, there will be a solution which 
> exactly fits the equations as written).  If you have more equations than 
> unknowns (overdetermined system), there can be an "exact" solution only 
> for infinite precision arithmetic.  

In general, you're sorta right.  The correct statement for a linear system
(Ax=b) is that the rank of A is the same as the number of unknowns.  If I have
more equations than unknowns but they some of them are superfluous, I'm still
good to go if the rank is right.

And generally w/ constraints, you can imagine I have superfluous constraints. 
E.g., let's say my system has an exact solution that is the vector 1.  If I add
the constraint that one of the variables is between 0 and 2, that won't upset
the apple cart.

Last, in the example code I sent out, there's an exact solution that I find if I
disable check_func...

thanks
sd