The "effective input" to exp in exp(I*x) is not real for any non-zero real value of x, so 0 is the only real point in the domain hence the solution is correct. I should clarify that the input function/equation of solveset_real are functions of real variable [1] and are also real-valued [2] functions. This means they should map a subset of real numbers to a subset of real numbers.
[1]: https://en.wikipedia.org/wiki/Function_of_a_real_variable [2]: https://en.wikipedia.org/wiki/Real-valued_function On 1 July 2015 at 23:28, Gaurav Dhingra <[email protected]> wrote: > Thanks for answering > Though i forgot put `-1` > Sorry > Now equation is `solveset_real(exp(I*x) - 1, x)` now this should return > `ImageSet(Lambda(_n, 2*_n*pi), Integers())` > but currently returns `FiniteSet(0)` what about this ? > > On Wednesday, July 1, 2015 at 11:24:07 PM UTC+5:30, Harsh Gupta wrote: >> >> > Though `solveset_real` claims to be complete in terms of real solution >> > returned >> >> Well, solveset_real assumes that you are working in a real system, >> that means both the equation and the solutions are in a real domain. >> So solveset_real expect users to input equations like `exp(I*x) = 0` >> and it should probably raise an error or maybe the doc string needs to >> be updated. As you have figured out for yourself if someone wants to >> work in the complex domain they can always use solveset_complex. >> >> >> On 1 July 2015 at 23:11, Gaurav Dhingra <[email protected]> wrote: >> > Hi all >> > Though `solveset_real` claimes to be complete in terms of real solution >> > returned >> > But for this >> > >> >>>> x = Symbol('x', real=True) >> >>>> solveset_real(exp(I*x), x) >> > FiniteSet(0) >> > >> > But probably the solution is what is returned for the `solveset_complex` >> >>>> y = Symbol('y') >> >>>> solveset_complex(exp(I*y), y) >> > >> > ImageSet(Lambda(_n, 2*_n*pi), Integers()) # correct solution returned >> > >> > # same should be returned for >> > `solveset_real` ? >> > >> > >> > Is there any reason why we just get `FiniteSet(0)` ? >> > >> > Cheers >> > >> > Gaurav >> > >> > -- >> > 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 [email protected]. >> > To post to this group, send email to [email protected]. >> > 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/fbf1e47b-3bab-4c7c-9099-25a2eef27062%40googlegroups.com. >> > For more options, visit https://groups.google.com/d/optout. >> >> >> >> -- >> Harsh > > -- > 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 [email protected]. > To post to this group, send email to [email protected]. > 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/dc3589c8-e9d7-40f6-b0ad-8810dedd5ae9%40googlegroups.com. > > For more options, visit https://groups.google.com/d/optout. -- Harsh -- 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 [email protected]. To post to this group, send email to [email protected]. 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/CADN8iuregzkJLu8AhhXgVZ4_za0j55KD7kor5Zcj44Dm-zt%2B1Q%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
