Determines the levels of a Directed Acyclic Graph (DAG)package:topGOR Documentation

_D_e_t_e_r_m_i_n_e_s _t_h_e _l_e_v_e_l_s _o_f _a _D_i_r_e_c_t_e_d _A_c_y_c_l_i_c _G_r_a_p_h (_D_A_G)

_D_e_s_c_r_i_p_t_i_o_n:

     TODO: This function take the a directed graph and constructs a
     named vector which contain the level on which a node is. The root
     has level 1.

     TODO: Find the root(roots) of the DAG

_U_s_a_g_e:

     buildLevels(dag, root = NULL, leafs2root = TRUE)
     getNoOfLevels(graphLevels)
     getGraphRoot(dag, leafs2root = TRUE)

_A_r_g_u_m_e_n_t_s:

     dag: ~~Describe 'dag' here~~ 

    root: ~~Describe 'root' here~~ 

leafs2root: The leafs2root parameter tell if the graph has edges
          directed from the leaves to the root, or vice-versa

graphLevels: ~~Describe 'graphLevels' here~~ 

_D_e_t_a_i_l_s:

     .....

_V_a_l_u_e:

     it returns a list containing: 

level2nodes: Environment where the key is the level number with the
          value being the nodes on that level.

nodes2level: Environment where the key is the node label (the GO ID)
          and the value is the level on which that node lies.

noOfLevels: The number of levels

noOfNodes: The number of nodes

_A_u_t_h_o_r(_s):

     Adrian Alexa

_S_e_e _A_l_s_o:

     'topGOdata-class', 'reverseArch', 'inducedGraph'

_E_x_a_m_p_l_e_s:

     ##---- Should be DIRECTLY executable !! ----
     ##-- ==>  Define data, use random,
     ##--    or do  help(data=index)  for the standard data sets.

