Get the unique layers or depths, i.e. the backbone of an object given a set of identifying columns.
Usage
depth_structure(x, id_cols = NULL, ...)
# S3 method for class 'cfp_layered_profile'
depth_structure(x, id_cols = NULL, ...)
# S3 method for class 'cfp_profile'
depth_structure(x, id_cols = NULL, ...)
# S3 method for class 'cfp_dat'
depth_structure(x, id_cols = NULL, structure_from = NULL, ...)