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Fixes for graph search examples (mr-8) #80

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Fixes for graph search examples (mr-8) #80

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4 changes: 2 additions & 2 deletions matlab_simulation/01-examples_lecture/mr-8-graphsearch/wavefront_example.m
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Original file line number Diff line number Diff line change
Expand Up @@ -6,12 +6,12 @@
startpos = [103, 480];
endpos = [110, 400];

[wavefrontmap, path] = wavefront(testimage, startpos, endpos);
[wavefrontmap, path] = wavefront(testimage, startpos, endpos, 'urdl');

% you can just run this function without rebuilding the wavefront map if the
% goal location (or end point) does not change.

path = shortest_wavefront_path(wavefrontmap, startpos);
path = shortest_wavefront_path(wavefrontmap, startpos, 'urdl');
imagesc(wavefrontmap);
hold on
plot(path(:,1), path(:,2), '-r');
Expand Down
46 changes: 23 additions & 23 deletions matlab_simulation/08-planning/shortestpath_mr.m
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Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@
% upper triangle
% start: index of start node
% finish: index of finish node
% method: (1 = Astar) (2 = Dijkstra's)
% method: (1 = Astar) (2 = BFS) (3 = DFS) (4 = Dijkstra's)
% heuristicDist: 1.Euclidean distance 2.Manhattan distance
% createVideo: (1 = YES) (the others: NO)
% Outputs:
Expand Down Expand Up @@ -50,7 +50,7 @@
n = length(nodes);
switch heuristicDist
case 1
if (method == 3) || (method == 4)
if (method == 2) || (method == 3)
disp('Error, use manhattan distance for breadth and depth first search')
return;
end
Expand Down Expand Up @@ -122,26 +122,6 @@
continue;
end

case 4 %Dijkstra's
% Check if open set is empty
if (isempty(OpenSet(:,1)))
spath = [];
sdist = 0;
return;
end
%--------------------------------
% Reminder: OpenSet(:,4)= distance to neighbours;
[val, best] = min(OpenSet(:,4));
%--------------------------------
bestnode = OpenSet(best,:);
% Check end condition
if (bestnode(1)==finish)
done = 1;
% Move best to closed set
C = [C; bestnode];
continue;
end

case 2 %Breadth-First
if (isempty(OpenSet(:,1)))
done = 1;
Expand Down Expand Up @@ -177,6 +157,26 @@
C = [C;bestnode];
continue;
end

case 4 %Dijkstra's
% Check if open set is empty
if (isempty(OpenSet(:,1)))
spath = [];
sdist = 0;
return;
end
%--------------------------------
% Reminder: OpenSet(:,4)= distance to neighbours;
[val, best] = min(OpenSet(:,4));
%--------------------------------
bestnode = OpenSet(best,:);
% Check end condition
if (bestnode(1)==finish)
done = 1;
% Move best to closed set
C = [C; bestnode];
continue;
end
end

% Move best to closed set
Expand Down Expand Up @@ -244,7 +244,7 @@
switch method
case 1 % Astar
OpenSet = OpenSet([1:best-1 best+1:end],:); % remove best node from open set
case 4 %Dijkstra's
case 4 % Dijkstra's
OpenSet = OpenSet([1:best-1 best+1:end],:); % remove best node from open set
end

Expand Down