void igraph_arpack_options_init(igraph_arpack_options_t *o);

Initializes ARPACK options, set them to default values. You can always pass the initialized igraph_arpack_options_t object to built-in igraph functions without any modification. The built-in igraph functions modify the options to perform their calculation, e.g. igraph_pagerank() always searches for the eigenvalue with the largest magnitude, regardless of the supplied value.

If you want to implement your own function involving eigenvalue calculation using ARPACK, however, you will likely need to set up the fields for yourself.

Arguments: 

Time complexity: O(1).