Parallel K-Means Clustering With Reducer Function - DZone AI

In functional programming, a fold is a higher-order function, also known as reduce and accumulate, whose purpose is to reduce a given data structure, typically a sequence of elements, into a single value. For example, a reduction could return an average value for a series of numbers, calculating a summation, maximum value, or minimum value. The fold function takes an initial value, commonly called the accumulator, which is used as a container for intermediate results. Then, the second argument it takes is a binary expression that acts as a reduction function to apply against each element in the sequence to finally return the new value for the accumulator. In general, reduction works as follows.