Hi! Does anybody have plans for releasing? Doing releases may have become unpopular among developers since the current version can always easily be pulled off from git. On the other hand, we've had quite a number of improvements and build fixes since 1.6.2, so it might be a good opportunity to officially get all this released. What do others think? And, in particular, @Alex and @Vladimir: do you have things in the pipeline? Cheers -richy. -- Richard B. Kreckel <http://www.ginac.de/~kreckel/>
Dear All,
On Sun, 03 Nov 2013 23:36:36 +0100, "Richard B. Kreckel" <kreckel@ginac.de> said: RK> And, in particular, @Alex and @Vladimir: do you have things in the pipeline?
I wish to propose another GiNaC extension. Consider function abs(). Since it can be presented as abs(z)=sqrt(z*z.conjugate()), the derivative of abs(f) may be calculated as (abs(f))'=(f'*f.conjugate()+f*f'.conjugate())/2/abs(f) However, this formula cannot be packed into the present GiNaC code, since it only knows about the chain rule. Thus, the patch adds a possibility to define derivatives of functions in some general expression. In particular, the above derivative of abs() is defined. Example: cout << abs(log(z)).diff(z) << endl; // (before) -> D[0](abs)(log(z))*z^(-1) // (now) -> 1/2*(z^(-1)*conjugate(log(z))+log(z)*conjugate(z)^(-1))*abs(log(z))^(-1) Best wishes, Vladimir -- Vladimir V. Kisil email: kisilv@maths.leeds.ac.uk www: http://www.maths.leeds.ac.uk/~kisilv/ Book: Geometry of Mobius Transformations http://www.worldscientific.com/worldscibooks/10.1142/p835
participants (2)
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Richard B. Kreckel
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Vladimir V. Kisil