Embodiments are disclosed for computing an eye diagram based on input pulse responses. An example method includes receiving a set of input pulse responses in one or more unit interval (UI) spaced samples. The set of input pulse responses is generated based on measuring a signal histogram of a receiver of a pulse amplitude modulation analog signal. The method further includes receiving a set of voltage range constraints and generating a matrix based at least in part on an element-wise trigonometric-based operation performed on one or more products of each element of the set of input pulse responses and the set of voltage range constraints. The method further includes generating an eye diagram probability density function based on the matrix and computing an eye diagram based on the eye diagram probability density function, the voltage range constraints, and time data associated with the one or more unit interval spaced samples.