44 lines
1.8 KiB
Matlab
44 lines
1.8 KiB
Matlab
function nextPos = basicGradientAscent(objectiveFunction, domain, pos, r)
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arguments (Input)
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objectiveFunction (1, 1) {mustBeA(objectiveFunction, 'function_handle')};
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domain (1, 1) {mustBeGeometry};
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pos (1, 3) double;
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r (1, 1) double;
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end
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arguments (Output)
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nextPos(1, 3) double;
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end
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% Evaluate objective at position offsets +/-[r, 0, 0] and +/-[0, r, 0]
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currentPos = pos(1:2);
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neighborPos = [currentPos(1) + r, currentPos(2); ... % (+x)
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currentPos(1), currentPos(2) + r; ... % (+y)
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currentPos(1) - r, currentPos(2); ... % (-x)
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currentPos(1), currentPos(2) - r; ... % (-y)
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];
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% Check for neighbor positions that fall outside of the domain
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outOfBounds = false(size(neighborPos, 1), 1);
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for ii = 1:size(neighborPos, 1)
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if ~domain.contains([neighborPos(ii, :), 0])
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outOfBounds(ii) = true;
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end
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end
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% Replace out of bounds positions with inoffensive in-bounds positions
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neighborPos(outOfBounds, 1:3) = repmat(pos, sum(outOfBounds), 1);
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% Sense values at selected positions
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neighborValues = [objectiveFunction(neighborPos(1, 1), neighborPos(1, 2)), ... % (+x)
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objectiveFunction(neighborPos(2, 1), neighborPos(2, 2)), ... % (+y)
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objectiveFunction(neighborPos(3, 1), neighborPos(3, 2)), ... % (-x)
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objectiveFunction(neighborPos(4, 1), neighborPos(4, 2)), ... % (-y)
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];
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% Prevent out of bounds locations from ever possibly being selected
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neighborValues(outOfBounds) = 0;
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% Select next position by maximum sensed value
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nextPos = neighborPos(neighborValues == max(neighborValues), :);
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nextPos = [nextPos(1, 1:2), pos(3)]; % just in case two get selected, simply pick one
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end |