In
mathematics, a
piecewise-defined function (also called a
piecewise function or a
hybrid function) is a
function which is defined by multiple sub-functions, each sub-function applying to a certain interval of the main function's domain (a sub-domain). Piecewise is actually a way of expressing the function, rather than a characteristic of the function itself, but with additional qualification, it can describe the nature of the function. For example, a
piecewise polynomial function is a function that is a polynomial on each of its sub-domains, but possibly a different one on each.