When setting up Reactor and Inlet properties, it is often desirable to specify a parameter that is not constant, but that varies as a function of the independent variable in the problem (for example, time or distance). In many cases, users have the option to specify a piece-wise linear profile that defines the functional variation of the parameter in terms of pairs of numbers. For example, a temperature profile may be defined that consists of (distance, temperature) pairs defining the temperature variation along a channel. The Profile tool facilitates creation, modification, and application of such profiles. The Profile tool can be accessed through the Edit > Profiles option, the Profiles icon on the Icon bar (in the menus interface), or the short-cut keystroke Ctrl-R. In addition, profiles can be created or edited within the Reactor input panels, where they will be applied to a specific parameter.