In signal processing, a window function (also known as an apodization function or tapering function) is a mathematical function that is zero-valued outside of some chosen interval. For instance, a function that is constant inside the interval and zero elsewhere is called a rectangular window, which describes the shape of its graphical representation. When another function or a signal (data) is multiplied by a window function, the product is also zero-valued outside the interval: all that is left is the part where they overlap; the "view through the window". Applications of window functions include spectral analysis, filter design, and beamforming.
A more general definition of window functions does not require them to be identically zero outside an interval, as long as the product of the window multiplied by its argument is square integrable, that is, that the function goes sufficiently rapidly toward zero.
In typical applications, the window functions used are non-negative smooth "bell-shaped" curves, though rectangle, triangle, and other functions are sometimes used.
Read more about Window Function: Applications, Window Examples, Comparison of Windows, Overlapping Windows, Two-dimensional Windows
Famous quotes containing the words window and/or function:
“Then is what you see through this window onto the world so lovely that you have no desire whatsoever to look out through any other window?—and that you even make an attempt to prevent others from doing so?”
—Friedrich Nietzsche (1844–1900)
“... the function of art is to do more than tell it like it is—it’s to imagine what is possible.”
—bell hooks (b. c. 1955)