Files
miSim/@miSim/lesserNeighbor.m

92 lines
3.0 KiB
Matlab

function obj = lesserNeighbor(obj)
arguments (Input)
obj (1, 1) {mustBeA(obj, "miSim")};
end
arguments (Output)
obj (1, 1) {mustBeA(obj, "miSim")};
end
% initialize solution with self-connections only
constraintAdjacencyMatrix = logical(eye(size(obj.agents, 1)));
nAgents = size(obj.agents, 1);
for ii = 1:nAgents
% Find lesser neighbors of each agent
% Lesser neighbors of ii are jj < ii in range of ii
lnBuf = zeros(1, nAgents);
lnCount = 0;
for jj = 1:(ii - 1)
if obj.adjacency(ii, jj)
lnCount = lnCount + 1;
lnBuf(lnCount) = jj;
end
end
obj.agents{ii}.lesserNeighbors = lnBuf(1:lnCount);
% Early exit for isolated agents
if lnCount == 0
continue
end
% Focus on subgraph defined by lesser neighbors
subgraphAdjacency = obj.adjacency(obj.agents{ii}.lesserNeighbors, obj.agents{ii}.lesserNeighbors);
% Find connected components; store only the max global index per
% component (the only value needed below) to avoid a cell array
visited = false(1, lnCount);
maxInComponent = zeros(1, lnCount);
numComponents = 0;
for jj = 1:lnCount
if ~visited(jj)
reachable = bfs(subgraphAdjacency, jj);
visited(reachable) = true;
numComponents = numComponents + 1;
maxInComponent(numComponents) = max(obj.agents{ii}.lesserNeighbors(reachable));
end
end
% Connect to the greatest index in each connected component in the
% lesser neighborhood of this agent
for jj = 1:numComponents
maxIdx = maxInComponent(jj);
constraintAdjacencyMatrix(ii, maxIdx) = true;
constraintAdjacencyMatrix(maxIdx, ii) = true;
end
end
obj.constraintAdjacencyMatrix = constraintAdjacencyMatrix | constraintAdjacencyMatrix';
end
function cComp = bfs(subgraphAdjacency, startIdx)
n = size(subgraphAdjacency, 1);
visited = false(1, n);
% Pre-allocated queue and component buffer with head/tail pointers
% to avoid element deletion and dynamic array growth
queue = zeros(1, n);
cCompBuf = zeros(1, n);
qHead = 1;
qTail = 2;
queue(1) = startIdx;
cCompBuf(1) = startIdx;
cSize = 1;
visited(startIdx) = true;
while qHead < qTail
current = queue(qHead);
qHead = qHead + 1;
% Find all neighbors of current node in the subgraph
neighbors = find(subgraphAdjacency(current, :));
for kk = 1:numel(neighbors)
neighbor = neighbors(kk);
if ~visited(neighbor)
visited(neighbor) = true;
cCompBuf(cSize + 1) = neighbor;
cSize = cSize + 1;
queue(qTail) = neighbor;
qTail = qTail + 1;
end
end
end
cComp = sort(cCompBuf(1:cSize));
end