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rtoy / maxima

A Clone of Maxima's repo
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functions abs or diff have a bug #1115

Open rtoy opened 2 months ago

rtoy commented 2 months ago

Imported from SourceForge on 2024-07-04 00:10:53 Created by lvch on 2013-01-17 12:01:15 Original: https://sourceforge.net/p/maxima/bugs/2534

Let declare(z,complex); depends(z,q);

So, diff(z,q,1) is complex variable and then abs(diff(z,q,1))^2 equal to diff(z,q,1)*conjugate(diff(z,q,1))

Maxima gives incorect result. It writes ('diff(z,q,1))^2

But it should be abs(diff(z,q,1))^2 or diff(z,q,1)*conjugate(diff(z,q,1)) or realpart(diff(z,q,1))^2+imagpart(diff(z,q,1))^2

rtoy commented 2 months ago

Imported from SourceForge on 2024-07-04 00:10:54 Created by robert_dodier on 2017-08-18 05:49:09 Original: https://sourceforge.net/p/maxima/bugs/2534/#0383

I believe the origin of this problem is that Maxima doesn't understand that the derivative of a complex variable is complex. I haven't thought about this very much yet, but I believe it should be relatively straightforward to fix it.

rtoy commented 2 months ago

Imported from SourceForge on 2024-07-04 00:10:58 Created by robert_dodier on 2017-08-19 19:28:17 Original: https://sourceforge.net/p/maxima/bugs/2534/#15cf