Piecewise linear function
（重定向自Piecewise linear map）
![A continuous piecewise linear function](/Images/godic/202502/02/Piecewise_linear_function.svg4351.png")
![A function (blue) and a piecewise linear approximation to it (red).](/Images/godic/202502/02/Finite_element_method_1D_illustration1.svg4351.png")
![A piecewise linear function in two dimensions (top) and the convex polytopes on which it is linear (bottom).](/Images/godic/202502/02/Piecewise_linear_function2D.svg4351.png")
In mathematics, a piecewise linear function is a real-valued function defined on the real numbers or a segment thereof, whose graph is composed of straight-line sections. It is a piecewise-defined function, each of whose pieces is an affine function.