Launch me!

What does this calculator do?

This calculator was created to accompany our new book on SPICE simulation of guitar amplifier circuits.¹ At one point in writing a large-signal triode model, a curve fit is required using quadratic regression. As a convenience for readers of the book, this calculator performs these calculations automatically. Specifically, the calculator computes optimal values of K1, K2, and K3 for the formula

A = K1(V_G)² + K2(V_G) + K3

The algorithm requires at least 3 data points and handles up to 9 data points. Leave unused inputs equal to "0".

References

¹Richard Kuehnel, Guitar Amplifier Electronics: Circuit Simulation, (Seattle: Amp Books, 2019).