y'=-y/(2*y^3-1)
maanantai 17. marraskuuta 2025 klo 18.21.42 UTC+2 [email protected] kirjoitti: > On Mon, Nov 17, 2025 at 3:45 AM [email protected] <[email protected]> wrote: > >> According to the manual the following should work: >> >> t,y=var('t,y'); >> g= lambda t,y:-y/(2*y^3 - 1); >> ra = ode_solver(); >> ra.function=g; >> ra.ode_solve(y_0=1,t_span=[0,1],num_points=100) >> > > > Please write the ODE you want to solve, in the usual maths notation - > it's not clear what it is. > > > >> >> However, I get the error message >> >> >> --------------------------------------------------------------------------- >> TypeError Traceback (most recent call last) >> /tmp/ipykernel_317/557462051.py in <module> ----> 1 ra.ode_solve(y_0= >> Integer(1),t_span=[Integer(0),Integer(1)],num_points=Integer(100)) >> /usr/lib/python3/dist-packages/sage/calculus/ode.pyx in >> sage.calculus.ode.ode_solver.ode_solve >> (build/cythonized/sage/calculus/ode.c:5124)() 412 self.y_0 = y_0 413 --> >> 414 dim = len(self.y_0) 415 type = isinstance(self.function,ode_system) >> 416 if type == 0: TypeError: object of type 'sage.rings.integer.Integer' >> has no len() >> >> Also >> def f(t,y): return -y/(2*y^3 - 1); >> ra.function=f; >> >> gives the same error. >> >> ?? >> >> -- >> You received this message because you are subscribed to the Google Groups >> "sage-support" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion visit >> https://groups.google.com/d/msgid/sage-support/d14332f8-44b6-4f93-9b42-0972926d2a16n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/sage-support/d14332f8-44b6-4f93-9b42-0972926d2a16n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- You received this message because you are subscribed to the Google Groups "sage-support" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/sage-support/48560c48-2cff-443b-94a4-30e071c6552en%40googlegroups.com.
