Re: [Gnucap-devel] Let me introduce myself

[Stuart Brorson]

> > Finally I would like to tell you an idea that I
> > thought. I told Al that I've taken courses in control
> > enginering and signal processing, on which I've used a lot
> > MATLAB/Octave. So I think it would be nice to have a way to
> > use the data generated by the simulator in MATLAB/Octave. I
> > had this idea because I thought it could be interesting to
> > have a this capabilities in the simulator.
>
> Welcome ...  You should also post to the gEDA list.  gEDA is the
> project listed with Google.
>
> Regarding using gnucap output in octave ...  I think it works
> now.  The gnucap format is just rows of data separated by
> spaces, which many programs can read.
>
> One project that would be very useful is the ability to write
> plugins in octave, maybe not all but just enough to do function
> evaluation.  I think this one is very difficult, likely too
> difficult for a summer.

I imagine the goal is to write a plant simulation in Octave, design a
control system using gschem, export a SPICE/gnucap netlist, and then
invoke gnucap analyses from within Octave while simulating the control
dynamics, right?

FWIW, I tried doing something similar using pipes to slave gnucap to
an octave simulation.  It didn't work well, because octave didn't
consistently flush its IO buffers, so gnucap was often left waiting
for input, while octave thought it was done giving gnucap the data.

However, the same thing works very well between Python/NumPy and
gnucap: You can easily write a Python program which uses a gnucap
slave to perform circuit analyses.  Communication via pipes works well
in this case.  I wrote an app note for my current employer detailing
how to do this in a parallel computer environment.

Apropos GSoC, my thought is this:  Maybe an interesting summer project
would be to create a set of Python bindings to gnucap, so you can
write Python/NumPy simulations which employ gnucap to perform circuit
analysis as part of a larger control system simulation.

I believe there are already gnucap bindings in Ruby, so Python
bindings would be pretty easy to implement using the Ruby bindings as
an example.  The advantage is Python is that it is much more well
known, and -- more importantly -- has a very nice numerical package
called NumPy which offers similar functionality to Matlab/octave.

Stuart