Let be a simple connected graph, and take , where is the graph diameter. Then has global parameters (respectively , ) if the number of vertices at distance (respectively, , ) from a given vertex that are adjacent to a vertex at distance from is the constant (respectively , ) depending only on (i.e., not on of ).

Global parameters may be computed by the `GRAPE` package in `GAP` using the function `GlobalParameters(`*G*`)`, which returns a list of
length
whose th
element is the list
(except that if some global parameter does not exist then is put in its place). Note that is a distance-regular
graph iff this function returns no in place of a global parameter.

A distance-regular graph with global parameters has intersection array .