cocoa touch - Is there a way to use UIView animations with custom ease equation -

uiview provides few easing options (uiviewanimationoptioncurveeasein, uiviewanimationoptioncurveeaseout, uiviewanimationoptioncurveeaseinout) animation, want more control on easing.

is there way provide custom equation, or in way more control on it? is, aside using touchesbegan: etc. roll own animations.

i think need use core animation this.
http://developer.apple.com/library/mac/#documentation/cocoa/conceptual/coreanimation_guide/introduction/introduction.html

using cakeyframeanimation ( http://developer.apple.com/library/mac/#documentation/graphicsimaging/reference/cakeyframeanimation_class/introduction/introduction.html#//apple_ref/occ/cl/cakeyframeanimation ) can customize timing of animaiton