A graphing method is implemented by a graphing apparatus and includes: (a) receiving a first value and a second value, and reference information corresponding to the first and second values; (b) determining an angle value using the first value and the second value, step (b) including (b-1) calculating a relational value by determining the quotient of a numerator and a denominator, in which the denominator is a function of the first value and the numerator is a function of at least the second value, and (b-2) obtaining the angle value by inputting the relational value in a predetermined inverse trigonometric function; (c) generating a graph having presented thereon a coordinate value formed using the angle value and the reference information; and (d) outputting the graph to a display medium for display thereon. A computer program product and a graphing apparatus are also disclosed.