thanks doug, thats a big help.

thanks for replying dude. i havent been having trouble with plotting solution curves. i think maybe i might abandon the quest for the arrows, its not going anywhere, i suspect that you cant produce them for a 2nd order ODE.

about the animation though, i want do see the change in a solution curve as i change a parameter in the original ODE. so i want to essentialy create an animation aout of lots of curves rather than animate a curve, any suggestions? i could make an array of curve with different values of the parameter but i'd quite like a smooth animation.

thanks a lot