To display a mass quantity of periodic data over continuous time zones in a compact form without impairing fidelity of the data.

In one embodiment, a process of generating a surface based on the periodic data is included, where the outline of this surface corresponds to the amplitudes of plural data points. At least one section 37 in the surface can be visually discriminated from the other section 39 in the surface. A rendering mode related to the surface, an eye orientation and/or a concern section 37 are set, and it can be renewed at real time or simulated time.