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| = Final Pynac Switchover Push for Sage-4.0 = See also http://trac.sagemath.org/sage_trac/ticket/5930 <<TableOfContents>> == Number Fields == * _pow_ in number_field_element and _rational_ has some hacks since the Pynac library will cause infinite recursions. == Formal Derivatives == * Handling of fderivatives so that we can convert to Maxima. == Doctest Grunt Work == * There's a lot of "grunt work" to be done to fix doctests to work with the new output format. In each case somebody has to verify that the two things are equal. == Massive Speed Regressions == * The massive speed regressions, making pynac symbolics *slower* than Maxima for some benchmarks. == I = sqrt(-1) == * The current handling of I as a wrapper around a number field element is a bit awkward since (I+2)*x can't be expanded as I+2 is "atomic". This also means that I.imag() returns 1.0 instead of 1. This causes issues in algebraic. Idea to solve this: {{{ Mike: I think what we want is just a QQ*I ring which automatically goes to SR when you do arithmetic with anything outside of it. me: ok. You suggested that before, and it makes some sense. Can't we just make a quadratic number field, and enhance it a tiny spec. Mike: I think if we had that, then everything should work out. Sent at 11:31 AM on Thursday me: That sounds easy enough, and it would be super fast, since quadratic fields are very very fast. Mike: We just don't have an exact way to work with complex numbers. me: robertwb could whip it out, as he wrote quadratic fields, etc. Mike: Yep For RR we have QQ, but we don't have quite an analogue for CC. }}} |
