selects values that you want using the number 1 with one dimension. list of zeroes and ones that specify which values are going to be kept (1) or discarded (0). with one dimension, and of the same size as the right inlet grid. with one dimension, and not bigger than the input grid. the size of the grid can be found with [# !=] [#fold +] on the right input grid. done another way used the normal way