1. A method for determining a transition-effect delay model for a timing arc of a library cell, the method comprising: receiving a discretized delay model for the timing arc of the library cell, wherein the discretized delay model is capable of being represented by a set of points in a multi-dimensional space, the multi-dimensional space including an output loading dimension, an input transition dimension, an output delay dimension, and an output transition dimension; and determining, by computer, a set of transition-effect coefficients for the timing arc of the library cell based on the discretized delay model, wherein each transition-effect coefficient represents a linear relationship between a change in output delay and a change in input transition for a corresponding output load value from a set of output load values.