Interesting behavior (not very creative, but hey, I'm an ODE noob): >>> dsolve(f-f.diff(x, 1), f) f(x) == exp(C1 + x) >>> dsolve(f-f.diff(x, 2), f) f(x) == C1*exp(x) + C2*exp(-x) >>> dsolve(f-f.diff(x, 3), f) f(x) == C1*exp(x) + (C2*sin(x*3**(1/2)/2) + C3*cos(x*3**(1/2)/2))*exp(-x/2) >>> dsolve(f-f.diff(x, 5), f) f(x) == C1*exp(-x/4 + x*5**(1/2)/4)*sin(x*(5/8 + 5**(1/2)/8)**(1/2)) + C2*exp(-x/4 + x*5**(1/2)/4)*sin(x*(5/8 + 5**(1/2)/8)**(1/2)) + C3*exp(-x/4 - x*5**(1/2)/4)*sin(x*(5/8 - 5**(1/2)/8)**(1/2)) + C4*exp(-x/4 - x*5**(1/2)/4)*sin(x*(5/8 - 5**(1/2)/8)**(1/2)) + C5*exp(x) + C6*cos(x*(5/8 + 5**(1/2)/8)**(1/2))*exp(-x/4 + x*5**(1/2)/4) + C7*cos(x*(5/8 + 5**(1/2)/8)**(1/2))*exp(-x/4 + x*5**(1/2)/4) + C8*cos(x*(5/8 - 5**(1/2)/8)**(1/2))*exp(-x/4 - x*5**(1/2)/4) + C9*cos(x*(5/8 - 5**(1/2)/8)**(1/2))*exp(-x/4 - x*5**(1/2)/4)
Don't know whether it makes sense to add this trivial special case. The other ODEs I "invented" were mostly not solvable. :( Do you think solve should recognize ODEs? >>> dsolve(f-f.diff(x), f) f(x) == exp(C1 + x) >>> solve(f-f.diff(x), f) [0] Vinzent --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sympy-patches" group. To post to this group, send email to sympy-patches@googlegroups.com To unsubscribe from this group, send email to sympy-patches+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sympy-patches?hl=en -~----------~----~----~----~------~----~------~--~---
