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| gnucap:manual:commands:options 2009/09/22 01:12 | gnucap:manual:commands:options 2010/06/03 00:49 current | ||
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| |dampmax |1. |Normal Newton damping factor. Sets the damping factor for iteration by damped Newton's method, used when all is well. It must be between 0 and 1, as close to 1 as possible and still achieve convergence. The useful range is from .9 to 1. Setting dampmax too low will probably cause convergence to a nonsense result. | | |dampmax |1. |Normal Newton damping factor. Sets the damping factor for iteration by damped Newton's method, used when all is well. It must be between 0 and 1, as close to 1 as possible and still achieve convergence. The useful range is from .9 to 1. Setting dampmax too low will probably cause convergence to a nonsense result. | | ||
| |dampmin |0.5 |Newton damping factor in problem cases. Sets the damping factor for iteration by damped Newton's method, used when there are problems. It must be between 0 and 1, and is usually set somewhat less than dampmax. The useful range is from .5 to .9. Setting it lower than .5 may cause convergence to a nonsense result. Aside from that, a lower value (but less than dampmax) tends to improve robustness at the expense of convergence speed. | | |dampmin |0.5 |Newton damping factor in problem cases. Sets the damping factor for iteration by damped Newton's method, used when there are problems. It must be between 0 and 1, and is usually set somewhat less than dampmax. The useful range is from .5 to .9. Setting it lower than .5 may cause convergence to a nonsense result. Aside from that, a lower value (but less than dampmax) tends to improve robustness at the expense of convergence speed. | | ||
| - | |dampstrategy |0 |Damping strategy. The actual damping factor to use is determined by heuristics. Normally the damping factor is dampmax. It is reduced to dampmin when certain conditions occur, then it drifts back up on subsequent iterations. | | + | |dampstrategy |0 |Damping strategy. The actual damping factor to use is determined by heuristics. Normally the damping factor is dampmax. It is reduced to dampmin when certain conditions occur, then it drifts back up on subsequent iterations. The strategy used is determined by the sum of the following factors:\\ 1: initial step: Use dampmin on the second iteration.\\ 2: range: Use dampmin if an iteration voltage would be out of range (vmin, vmax).\\ 4: device limiting: Use dampmin when device based voltage or current limiting limits. (If supported by the device.)\\ 10: device region: Use dampmin when a device passes a region boundary (If supported by the device.)\\ 20: device reverse: Use dampmin when a device is reversed. (If supported by the device.) | |