Methods and apparatuses disclose various embodiments of time-domain signal generation. In one embodiment a method includes receiving an input waveform having a plurality of cycles with aspects of the input waveform being input and controllable by an end-user. A set of transform coefficients is calculated for at least some of the cycles using at least one hardware-based processor. A time-domain cycle is calculated for each set of transform coefficients. Other methods and apparatuses are disclosed.