This function returns a neighborhood that behaves as nhood, except that the neighborhood order is randomly jumbled each time that the returned neighborhood is started. The argument rand is used to generate the required random numbers. The optional argument name, if provided, becomes the name of the returned neighborhood. The returned neighborhood uses memory linear in the size of the neighborhood nhood to store the randomization order.

This type of randomized neighborhood is extremely useful in local search procedures, as neighbors with low indices are often preferred to those with high indices simply because they are examined first. This can lead to a stagnation in the search process, which can be avoided with the use of a randomized neighborhood.