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Differentiation of scalar variables

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I have been doing some fairly straightforward computations of the IdVg response of nanowire transistors. As part of the compuation I want to get a quick and dirty visualization of the transconductance, without doing small signal AC analysis. Essentially all I want is the first derivative of the Idvg curve with respect to Vg. Initially I tried d(semi.I0_1, semi_V03) where terminals 1 and 3 are the drain and gate, respectively. That gave me zeros all across. I then drived a number of variations, all of which produced zeros. Then I came across the above referenced thread that, in the last post, points to a workaround with a specific example for spatial derrivatives.

https://www.comsol.com/blogs/plotting-spatial-derivatives-magnetic-field/

However, I am either too dumb to adapt this to a scalar variable such as current, or this only works for spatial derrivatives. Is there a quick and easy way to do this? And if not, why not :-)


0 Replies Last Post 2018年7月28日 GMT-4 22:34
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Hello Boyan Boyanov

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