Graph Coloring

The graph_color_symbolic function resides in the KokkosGraph::Experimental namespace. A kernel handle is used to set options such as execution space, memory space, team size, and which algorithm implementation is used.

Header File: KokkosGraph_graph_color.hpp

Usage:

KokkosGraph::Experimental::graph_color (
    KernelHandle *handle,
    typename KernelHandle::nnz_lno_t num_rows,
    typename KernelHandle::nnz_lno_t num_cols,
    lno_row_view_t_ row_map,
    lno_nnz_view_t_ entries,
    bool is_symmetric = true)

Requirements:

row_map and entries represent the graph in compressed sparse row format
num_rows == num_cols
The input graph must be structurally symmetric, meaning that if (i,j) is an entry, then so is (j,i).
- Except: any entry (i,j) where j >= num_rows is ignored. This is useful for coloring the local subgraph of a distributed matrix.
Diagonal entries (self-loops) are ignored.

Outputs:

Get the view of colors: handle->get_graph_coloring_handle()->get_vertex_colors();
- Note: color values use 1-based numbering, i.e. 1 is the first color and so on.
Get the number of colors used: handle->get_graph_coloring_handle()->get_num_colors()