Beyond SPICE

So here I am, working on a new version of my previous SPICE software.  Of course to call something SPICE, it's usually a linear circuit simulator.  When you start adding nonlinear models with S-Parameter, Harmonic Balance, and Various Large-Signal simulations you start to move past SPICE into something a little more :).  So I have named this new version Beyond SPICE to show that it will be greater than a simple SPICE software.

So, in this I have started to create the basis of the software within the last 2 weeks.  I'm starting (for the most part) from scratch.  My last version was simply able to handle transient analysis for Resistors/Capacitors/Inductors/Current Source/Voltage Source.

This new version will handle this plus everything else.

Up to this point, I have the following elements in there first versions:

• Complex Numbers and Parser:
• The parser can parse directly to a complex number or can separate the equation into an expression tree.  I will explain this in another post.
• Can handle all variations of complex number and functions including hyperbolic functions.
• Matrices:
• A number of matrix classes have been created.  Namely, a string matrix, complex constant matrix, and an expression tree matrix.
• Complex Constant Matrix and Expression Tree Matrix can be inverted along with determinants.  The simple things

Although, this may not seem like much, the value in the time spent in these 2 major class libraries has a vast impact on the speed of the final product.  For instance, the Expression Tree allows for a complex statement to be parsed only once and evaluated many times (POEM - Parse Once Evaluate Many).  This means that parsing doesn't need to occur directly every iteration.  In fact, incorporating this into a matrix speeds up the time even more.

Secondly, having the invertability of the Expression Tree Matrix allows for inversion to only occur once and then evaluate the inverse matrix directly without having to perform the inverse at each time step.

Taking the time to develop these algorithms will show great improvement in performance down the road.

Hopefully I can keep you guys up to date more often.  Any questions, feel free to email me.

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Justin Coulston
justin.coulston@gmail.com