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Next: 4.2 The Quasi Full-Newton Up: 4.1 The Two-Level Newton Previous: 4.1.1 Calculation of Conductances

4.1.2 Modified Two-Level Newton Algorithm

A linear prediction step can be used to obtain an initial-guess from the previous solution. The two-level Newton scheme with a linear prediction step is referred to as the modified two-level Newton algorithm. A first-order prediction is made by use of the forward-Euler scheme,

xk + 1 = xk + $ \left.\vphantom{ \frac{\partial \mathbf{x}}{\partial V} }\right.$$ {\frac{\partial \mathbf{x}}{\partial V}}$ $ \left.\vphantom{ \frac{\partial \mathbf{x}}{\partial V} }\right\vert _{k}^{}$ . $ \Delta$V (4.12)

where $ \Delta$V is the change in voltage from circuit iteration k to k + 1, and $ \partial$x/$ \partial$V is calculated as in (4.8). In the investigations of [39] this algorithm had the most reliable convergence properties.

Tibor Grasser