I realized that you may be just looking for the Python complex type. To get that you can do: sage: j = complex(i) sage: (3 + 4*j)^2 (-7+24j)
Here are some other options. The first involves using number field arithmetic, so it may not be what you want (you can't use floating point values in the results): sage: Q.<j> = QuadraticField(-1) # for an exact version sage: (3 + 4*j)^2 24*j - 7 If you just want j in the input and don't care about the output display, that's easy: sage: j = i # for the symbolic ring sage: (3 + 4*j)^2 24*I - 7 sage: j = CDF.gen(0) # for double precision sage: (3 + 4*j)^2 -6.999999999999997 + 24.0*I sage: C.<j> = ComplexField(100) # higher precision sage: (3 + 4*j)^2 -7.0000000000000000000000000000 + 24.000000000000000000000000000*I David On Fri, Apr 12, 2019 at 1:59 PM rjf <fate...@gmail.com> wrote: > why not just use j, and tell sage that j^2=-1? > Depends on how much of Sage you > expect to understand this. > > (the use of j is common in electrical engineering, > for those who have not encountered this before...) > If you just want to be able to use j in your input (rather than having complex numbers display with j): sage: j = i # for the symbolic ring sage: 3 + 4*j 4*I + 3 sage: Q.<j> = QuadraticField(-1) # for an exact version sage: 3 + 4*j 4*j + 3 RJF > > On Friday, April 12, 2019 at 1:39:51 AM UTC-7, David Roe wrote: >> >> Is this what you're looking for? >> >> sage: z = ComplexNumber(1,2) >> sage: z >> 1.00000000000000 + 2.00000000000000*I >> sage: print z.str(istr='j') >> 1.0000000000000000 + 2.0000000000000000*j >> >> I don't think there's a global way to do this in Sage. I'm also not >> quite sure which kind of complex number you're working with; can you >> provide Sage commands? >> David >> >> On Fri, Apr 12, 2019 at 4:23 AM <nghi...@moet.edu.vn> wrote: >> >>> Hello everybody, >>> Ín sage, how change complex number symbols: >>> i^2=-1, z=a+bi >>> Now I want >>> j^2=-1, z=a+bj >>> Thank you! >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "sage-devel" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to sage-...@googlegroups.com. >>> To post to this group, send email to sage-...@googlegroups.com. >>> Visit this group at https://groups.google.com/group/sage-devel. >>> For more options, visit https://groups.google.com/d/optout. >>> >> -- > You received this message because you are subscribed to the Google Groups > "sage-devel" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sage-devel+unsubscr...@googlegroups.com. > To post to this group, send email to sage-devel@googlegroups.com. > Visit this group at https://groups.google.com/group/sage-devel. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
