On Mar 28, 9:01*pm, jeffs87 wrote:
No, I'm trying to design a op-amp filter and then convert that to code
to use in an audio program I'm working on. * I have a few FIR and IIR
filters working, but the filter I'm working on now is a little
unusual, so I'm trying to get it working in an electronic circuit
simulator first, then make a dsp version.

MacSpice is a simulator and takes instructions from a text
decscription of the circuit (a netlist). The process of translarting a
circuit diagram into a netlist is known as 'schematic capture' and the
first answer on the MacSpice FAQ lists several applications that
perform this process:

http://www.macspice.com/FAQ.html

MacSpice has a range of methods to allow it to communicate with other
applications. It can send and receive AppleEvents (e.g. AppleScript),
read and write to files, and execute shell scripts:

http://www.macspice.com/Interprocess.html

It's not clear to me exactly what your goals are, but you could try
using MacSpice to perform a pole-zero analysis of your circuit and
then use these values to parameterise the real circuit within your own
program.

Charles

(BTW, I am the developer of MacSpice. I don't normally read this
group, I'm just passing through while looking for something else,)