Re: [sympy] diff(x^x,x)
Actually, that's not quite true. SymPy has its own boolean types, and x ^ x gives the SymPy BooleanFalse (S.false). The derivative of this is 0 not because it interprets it as a numeric 0 but because it doesn't depend on x, and diff automatically knows that the derivative of any expression that doesn't depend on x is 0. Perhaps we should make derivatives of booleans give TypeError. That would make it much easier to see what is going on. It may also be worth it to print a warning in SymPy Live when ^ is used. Aaron Meurer On Sat, May 30, 2015 at 1:01 PM, Christophe Bal projet...@gmail.com wrote: And because x^x means x xor x which numeric value is 0 or 1 so the derivative is equal to zero. Christophe BAL Enseignant de mathématiques en Lycée et développeur Python amateur --- French math teacher in a Lycée and Python amateur developer -- You received this message because you are subscribed to the Google Groups sympy group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAAb4jG%3DudR3U3EG2VDUW5qdAG5TEo8HBxTDWc8f3_4f9a20Vjw%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups sympy group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAKgW%3D6KPDAgP%3DdWcomB98OFiED8qdmOVBNfTvK8OttvvfbVs7Q%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
Re: [sympy] diff(x^x,x)
Am 31.05.2015 um 22:50 schrieb Aaron Meurer: Perhaps we should make derivatives of booleans give TypeError. That would make it much easier to see what is going on. +1 Similarly, integer-valued functions should (probably?) emit a warning if a derivative is taken. The derivative is technically correct, but usually not what one wanted. It may also be worth it to print a warning in SymPy Live when ^ is used. I'll be all for it if somebody picks that up. -- You received this message because you are subscribed to the Google Groups sympy group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/556B7A6C.4030009%40durchholz.org. For more options, visit https://groups.google.com/d/optout.
Re: [sympy] diff(x^x,x)
I also vote for the TypeError. Le 31 mai 2015 23:17, Joachim Durchholz j...@durchholz.org a écrit : Am 31.05.2015 um 22:50 schrieb Aaron Meurer: Perhaps we should make derivatives of booleans give TypeError. That would make it much easier to see what is going on. +1 Similarly, integer-valued functions should (probably?) emit a warning if a derivative is taken. The derivative is technically correct, but usually not what one wanted. It may also be worth it to print a warning in SymPy Live when ^ is used. I'll be all for it if somebody picks that up. -- You received this message because you are subscribed to the Google Groups sympy group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/556B7A6C.4030009%40durchholz.org. For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups sympy group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAAb4jGk%3DYo2Wx4AOm83LDyKgZwGxU79FWxzeUAKA1tsqZWCWcw%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
Re: [sympy] diff(x^x,x)
And because *x^x* means *x xor x* which numeric value is *0* or *1* so the derivative is equal to zero. *Christophe BAL* *Enseignant de mathématiques en Lycée **et développeur Python amateur* *---* *French math teacher in a Lycée **and **Python **amateur developer* -- You received this message because you are subscribed to the Google Groups sympy group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAAb4jG%3DudR3U3EG2VDUW5qdAG5TEo8HBxTDWc8f3_4f9a20Vjw%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
Re: [sympy] diff(x^x,x)
In [1]: x^x Out[1]: False In [2]: diff(False, x) Out[2]: 0 You should use instead of *^* if you'd like to represent exponentiation. The symbol ^ stands for XOR. On Friday, 29 May 2015 23:17:11 UTC+2, Oscar wrote: On 29 May 2015 22:06, Thomas Leitz unruh...@gmail.com javascript: wrote: Hi, the online shell at http://live.sympy.org/ tells me diff(x^x,x) = 0 Why is that? ^ doesn't do what you're expecting in Python. Use ** for exponentiation. -- Oscar -- You received this message because you are subscribed to the Google Groups sympy group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/39df2b7e-b133-4c5c-ab4d-f535cd9c3df2%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
[sympy] diff(x^x,x)
Hi, the online shell at http://live.sympy.org/ tells me diff(x^x,x) = 0 Why is that? Tom -- You received this message because you are subscribed to the Google Groups sympy group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/5f6df3dd-904b-4d1a-afcc-9ce8ff0d7a50%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
Re: [sympy] diff(x^x,x)
On 29 May 2015 22:06, Thomas Leitz unruhsc...@gmail.com wrote: Hi, the online shell at http://live.sympy.org/ tells me diff(x^x,x) = 0 Why is that? ^ doesn't do what you're expecting in Python. Use ** for exponentiation. -- Oscar -- You received this message because you are subscribed to the Google Groups sympy group. To unsubscribe from this group and stop receiving emails from it, send an email to sympy+unsubscr...@googlegroups.com. To post to this group, send email to sympy@googlegroups.com. Visit this group at http://groups.google.com/group/sympy. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAHVvXxSNEU1dGr9zKOXRq1uFQYYEz10qHNku0JmzGmCqBhAq2w%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
