neighborhood_sorting_wrapper: A wrapper function for Neighborhood sorting.
In uSORT: uSORT: A self-refining ordering pipeline for gene selection

A wrapper function for Neighborhood sorting as proposed in [Tsafrir et al. 2005].

1	neighborhood_sorting_wrapper(expr, sigma_width = 1, no_randomization = 10)

`expr`	An expresssion matrix containing n-rows of cells and m-cols of genes.
`sigma_width`	An integer number determining the degree of spread of the gaussian distribution which is used for computing weight matrix for Neighborhood sorting method.
`no_randomization`	An integer number indicating the number of repeated sorting, each of which uses a randomaly selected initial cell ordering.