Unpack and Merge Data

Decompose a high-dimensional data list and merge the sub-lists in it.

This Step is widely used for dimensionality reduction. It can decompose the data list, and merge the elements after decomposition. It is usually used to reduce dimensionality of high-dimensional data. For example, if the input list is \[[5], [6], [7]], the output can be [5, 6, 7].