MovingMap¶

Apply a function to a sliding window.

(With the literal Mean symbol, Wolfram evaluates the window numerically, so real-valued input is used here to keep both engines in agreement.)

$ wo 'MovingMap[Mean, {1., 2., 3., 4., 5.}, 3]'
{2.5, 3.5}

The window function may be a pure function.

$ wo 'MovingMap[(#[[1]]*#[[2]]) &, {1, 2, 3, 4}, 1]'
{2, 6, 12}

A fourth argument pads the data on the left, so every input position gets a full window and the result keeps the input's length. "Fixed" repeats the first element, "Periodic" wraps around from the end, "Reflected" mirrors about the first element, and anything else is a constant fill.

$ wo 'MovingMap[Identity, {1, 2, 3}, 1, "Fixed"]'
{{1, 1}, {1, 2}, {2, 3}}

$ wo 'MovingMap[Total, {1, 2, 3, 4, 5}, 1, 0]'
{1, 3, 5, 7, 9}