Talk:Resistor mesh: Difference between revisions

→‎Link to a solution: Added number and link to exact solver
(non, wrong, these are equations between voltages, and V(A)=0, the current in B comes from V(B)=RI+V(A)=RI)
(→‎Link to a solution: Added number and link to exact solver)
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:: Of course the interesting part is how to get the voltage values, and there are multiple ways to do it. The C code just give the circuit some arbitrary values initially, then at each iteration calculates how much voltage difference is needed on each node to locally sastisfy the current flow constraint on that node, and adds it onto the voltage. For this task it converges and pretty quickly at that. --[[User:Ledrug|Ledrug]] 15:45, 29 August 2011 (UTC)
:::Given the problem size, even Gauss pivoting will do. Now, for a larger circuit, you would simply use a sparse symmetric solver, and there are many good ones already written. Maybe conjugate gradient would be a nice starting point. See also Maxima solution for an exact value. At least it will help checking other methods ;-) [[User:Capra Hircus|Capra Hircus]] 11:11, 28 August 2012 (UTC)
: The exact solver ([http://kirr.homeunix.org/electronics/resistor-network-solver/ link to solver]) gives 455859137025721/283319837425200, or approximately 1.60899124 Ohm. I now added this problem as example (to [http://kirr.homeunix.org/electronics/resistor-network-solver/?page=examples examples page]). The solver uses repetitive star-mesh transform, and it can list all steps that it took. In this case it takes over a 1000 steps - certainly not something you'd do by hand.
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