Mon 2018-01-15 07:00:03 UTC, Ralf Stephan: > > expr.poly(x) does not really make expr a polynomial in x, it's a quite useless method. > If you give no parameter to ex.coefficients() it takes the lexicographically first variable. > So instead of ex.poly(x).coefficients do ex.coefficients(x), and you get: > > sage: (zeta*diff(f(tau), tau)).coefficients(tau) > [[zeta*diff(f(tau), tau), 0]] > sage: (zeta*diff(f(tau), tau)).coefficients(zeta) > [[diff(f(tau), tau), 1]] > sage: (a*diff(f(b), b)).coefficients(a) > [[diff(f(b), b), 1]] > sage: (a*diff(f(b), b)).coefficients(b) > [[a*diff(f(b), b), 0]]
Should there be a note about that in the documentation of the `poly` method for symbolic expressions? -- 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 [email protected]. To post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
