Independent Variable
From ExoDictionary
Independent Variable
Any of those variables of a problem, chosen according to convenience, which may arbitrarily be specified, and which then determine the other or dependent variables of the problem.
The independent variables are often called the coordinates, particularly in problems involving motion in space. Dependent and independent variables can be interchanges, e.g., height and pressure.
References
This article is based on NASA's Dictionary of Technical Terms for Aerospace Use
