simple-statistics
Version:
22 lines (20 loc) • 654 B
JavaScript
/**
* When adding a new value to a list, one does not have to necessary
* recompute the mean of the list in linear time. They can instead use
* this function to compute the new mean by providing the current mean,
* the number of elements in the list that produced it and the new
* value to add.
*
* @since 2.5.0
* @param {number} mean current mean
* @param {number} n number of items in the list
* @param {number} newValue the added value
* @returns {number} the new mean
*
* @example
* addToMean(14, 5, 53); // => 20.5
*/
function addToMean(mean, n, newValue) {
return mean + (newValue - mean) / (n + 1);
}
export default addToMean;