A famous mathematical function, often found when it is needed to solve equations with a linear term and either a logarithmic or exponential term, is lacking in the Qucs family: the Lambert's W function. https://en.wikipedia.org/wiki/Lambert_W_function
Most numerical computation softwares (Maple, Mathematica, Matlab, Scilab, Octave, Python, etc.) have this feature. Because this function can solve many problems that can be found in electronic circuits involving diodes or bipolar transistors, I think it would be useful to see it in the Qucs family.
There are some papers which give some examples of such electronicn cirucits, and even Wikipedia mentions the "diode and resistor" circuit solving with this function.
I don't have a GitHub account, where most software development activities (Qucs-S) can be found, so I cannot make this suggestion there.
Thanks!
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I think the problem with posting this here is that QUCS/Qucsator is not seeing much active development. And if I (not a user) understand it, QUCS-S is a graphical interface to several back-end simulators and has no mechanism to evaluate functions. Posting a feature request for NGspice (here on Sourceforge) or another of the supported simulators may be the way to make progress.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
On Wed, Oct 23, 2024 at 01:26:56PM -0000, Giles Atkinson wrote:
I think the problem with posting this here is that QUCS/Qucsator is not seeing much active development.
The QUCS repo on sourceforge only acts as a mirror for the Qucs GUI
nowadays. The original simulator shipped with it, Qucsator, has been
decommissioned.
We have Gnucsator, a replacement for Qucsator, now offering most Qucs
devices and moderatly advanced stuff with Verilog-A, with more to come.
The full integration into QUCS is intended and will happen sooner or
later, see qucs/ROADMAP.
The Verilog-AMS LRM does not mention LambertW. Yet additional functions
are explicitly allowed by the standard. All those functions are plugins.
You can share one, and I will add it, but there is no technical need to.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
So there is this site (mostly inactive) and qucs and qucs-s on github, both active. I think it would help users if there were prominent notices on all three sites to explain the situation.
And the OP seems to have gone silent ...
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
In the meantime, if someone also needs this function for postprocessing (or device modelling?), this thread can be a good place for letting us know.
A few more useful materials to my previous post's mention of existing research about the Lambert W function in the analog electronics domain:
"Recent Applications of Lambert's W Function in Nanodevice Modeling Introduction", 2024, https://www.researchgate.net/publication/380637830_Recent_Applications_of_Lambert%27s_W_Function_in_Nanodevice_Modeling_Introduction (open access)
"Bipolar transistor circuit analysis using the Lambert W-function", 2002, https://ieeexplore.ieee.org/document/895330 (restricted access)
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Hi all,
A famous mathematical function, often found when it is needed to solve equations with a linear term and either a logarithmic or exponential term, is lacking in the Qucs family: the Lambert's W function.
https://en.wikipedia.org/wiki/Lambert_W_function
Most numerical computation softwares (Maple, Mathematica, Matlab, Scilab, Octave, Python, etc.) have this feature. Because this function can solve many problems that can be found in electronic circuits involving diodes or bipolar transistors, I think it would be useful to see it in the Qucs family.
There are some papers which give some examples of such electronicn cirucits, and even Wikipedia mentions the "diode and resistor" circuit solving with this function.
I don't have a GitHub account, where most software development activities (Qucs-S) can be found, so I cannot make this suggestion there.
Thanks!
I think the problem with posting this here is that QUCS/Qucsator is not seeing much active development. And if I (not a user) understand it, QUCS-S is a graphical interface to several back-end simulators and has no mechanism to evaluate functions. Posting a feature request for NGspice (here on Sourceforge) or another of the supported simulators may be the way to make progress.
On Wed, Oct 23, 2024 at 01:26:56PM -0000, Giles Atkinson wrote:
The QUCS repo on sourceforge only acts as a mirror for the Qucs GUI
nowadays. The original simulator shipped with it, Qucsator, has been
decommissioned.
We have Gnucsator, a replacement for Qucsator, now offering most Qucs
devices and moderatly advanced stuff with Verilog-A, with more to come.
The full integration into QUCS is intended and will happen sooner or
later, see qucs/ROADMAP.
The Verilog-AMS LRM does not mention LambertW. Yet additional functions
are explicitly allowed by the standard. All those functions are plugins.
You can share one, and I will add it, but there is no technical need to.
So there is this site (mostly inactive) and qucs and qucs-s on github, both active. I think it would help users if there were prominent notices on all three sites to explain the situation.
And the OP seems to have gone silent ...
Hi,
Thanks for reacting.
I have posted a suggestion on the GitHub page of Qucsator:
https://github.com/Qucs/qucsator/issues/50
In the meantime, if someone also needs this function for postprocessing (or device modelling?), this thread can be a good place for letting us know.
A few more useful materials to my previous post's mention of existing research about the Lambert W function in the analog electronics domain: