Function flann_sys::flann_radius_search

pub unsafe extern "C" fn flann_radius_search(
    index_ptr: flann_index_t, 
    query: *mut f32, 
    indices: *mut c_int, 
    dists: *mut f32, 
    max_nn: c_int, 
    radius: f32, 
    flann_params: *mut FLANNParameters
) -> c_int

Performs an radius search using an already constructed index.

In case of radius search, instead of always returning a predetermined number of nearest neighbours (for example the 10 nearest neighbours), the search will return all the neighbours found within a search radius of the query point.

The check parameter in the FLANNParameters below sets the level of approximation for the search by only visiting "checks" number of features in the index (the same way as for the KNN search). A lower value for checks will give a higher search speedup at the cost of potentially not returning all the neighbours in the specified radius.