[igraph] random generator graph in C

[alex]

Hi, i'm using the igraph directly in my C code. what i do is that i 
generate my graph using the igraph_grg_game function. I have 3 questions:

1- the two last input for this function igraph_grg_game (2 igraph 
vector), what are they role ? it's not explained in documentation.
2- I want to browse my graph generated to computes somes properties for 
each vertices. How can i dot it ?
3-  from my random graph, can i have a binary matrix (like 
igraph_matrix) that describes my graph (like topology matrix i.e 
matrix[i][j] = 1 if i and j are connected; 0 otherwise.

thank you for your help