1. A method of generating dose data comprising: generating, by a computer, virtual measurement data by mirroring, to a non-shot region outside a shot region with respect to an edge of the shot region, dimension measurement data in a measurement region inside the shot region, the shot region: being a region to be exposed at a time of exposure during a photolithography process, and including: the measurement region, and a non-measurement region other than the measurement region; and calculating, by a computer, the dose data of the measurement region and the non-measurement region, based on the dimension measurement data and the virtual measurement data.